Biography Category
Name :
Leeuwenhoek
Date :
Views :
543
Category :
Birth Date :
24/10/1632
Birth Place :
Delft, Netherlands
Death Date :
August 26, 1723
Not Available
In 1673, the Royal Society of London received an envelope, containing a lengthy and strange letter. At first, the members of the society had a hearty laugh reading the funny letter. It was not written by any scientist but a Dutch shopkeeper, who earned his living doubling as a part-time watchman besides running his small shop.[br /]
[br /]
In the first paragraph of the letter, the humble shopkeeper had written about his health and wished for the well-being of the society members. Mentioning about his neighbors, he described their superstitions. The members poked fun at him while it was being read. Suddenly, everyone stopped laughing. Astonishment and awe clearly lit on their faces. All eyes stuck on a title at the beginning of the next paragraph. The title read :[br /]
[br /]
Some unique specimen observed under the microscope constructed by Mr. Leeuwenhoek displaying skin cells.[br /]
[br /]
It was surprising ! They studied the whole letter calmly with interest. In the end, the members unanimously concluded that an almost illiterate Dutch shopkeeper had certainly discovered new kind of ‘creatures’.[br /]
[br /]
In return, they sent an appreciation letter to the shopkeeper, encouraging him to continue his experiments in the chosen direction. As a result, the Royal Society of London got around 165 (the figure is debatable) worthy letters from the Dutchman Antonie Van Leeuwenhoek, in the next 50 years. These letters brought a revolutionary change in the field of science, opening a new vista, of Microbiology.[br /]
[br /]
[b]Early Years[/b][br /]
[br /]
Little is known of Leeuwenhoek’s early life. Born on October 24, 1632, at Delft city of Holland [Netherlands], the Leeuwenhoeks, were not a well-to-do family. Although they had maintained their position in the society, the trades adopted were making and selling bamboo baskets and liquor.[br /]
[br /]
Antonie’s family name ‘Leeuw-en-hoek’ is often quite difficult to spell for non-Dutch people. The pronunciation ‘layu-wen-hook’ is a passable English approximation. It is said to be concerned with the location of his house situated at the corner (hoek) of the Lion’s (Leeuw) gate in the Delft City, then. Whether there was a tradition of deriving the family name from the local place or not, is still uncertain.[br /]
[br /]
Antonie’s father, Philips Leeuwenhoek was a basket-maker by profession and his mother, Margaretha Bel van den Berch belonged to a family of beer brewers. Antonie lost his father at the age of five. His mother Margaretha remarried Jacob Molijn, a painter and also a bailiff, after a three-year span.[br /]
[br /]
[b]Teenage Years[/b][br /]
[br /]
Antonie received little education at the town of Warmond during his early years. But he didn’t get exposure to the scientific knowledge of that time. Whatever little education he had, it was in his mother tongue – Dutch and he never had the opportunity to learn second language.[br /]
[br /]
In those days, Latin was considered the scientific language and most of the scientific works were available in Latin only. As Leeuwenhoek didn’t know Latin, he was unaware of the works of other scientists.[br /]
[br /]
Antonie spent some of his teenage years at Benthuizen with his uncle. During that period, his stepfather died in 1648. Now, Antonie was left to fend for himself. Soon, he got a job as an apprentice to a textile merchant William Davidson, in Amsterdam.[br /]
[br /]
Antonie aged 16, packed off his bags for the big city of Amsterdam leaving behind memories of his birthplace Delft – the lovely city breathing in the rippling sound of the water flowing through canals, and the beautiful view of the windmills under the blue sky.[br /]
[br /]
[b]Hobby Becomes Habit[/b][br /]
[br /]
During his five-year stay at Amsterdam, Leeuwenhoek sat at the Cloth Worker’s Guild examination. Generally, it took 3 years to pass the exams, but Leeuwenhoek took only 6 weeks ! At this point of time, Leeuwenhoek was introduced to magnifying glasses that were used to count thread density.[br /]
[br /]
When he was 21, he decided to spend the rest of his life at his native place. Returning to Delft, he bought a house at the Hippolytusburt, also called as ‘The Golden Head’, and opened a small shop there. Leeuwenhoek set himself up in business as a draper (a fabric merchant) and haberdasher. He married Barbara de Mey, daughter of a silk merchant. Meanwhile, he also worked as a surveyor and a wine assayer.[br /]
[br /]
Four years after opening the shop, Leeuwenhoek obtained a post of minor civic official that was ‘a position as chamberlain to the sheriffs of Delft’. His duties included sweeping the council room, arranging the decor, lighting the fire ‘at the proper time’ and also ‘preserving any coal that might be left unconsumed. ’Though his position was as the main servant of Delft Town Council that was of lower category, he used to conduct his duties diligently. He was not a rich person, but the two important characteristics of his nature were the best in itself – curiosity and enthusiasm.[br /]
[br /]
In his days, ordinary lenses were used for magnifying the tiny object and the best use then of it was to estimate the correct density of the fabric strand, of which, he was quite conversant with. It was not much remarkable and had to be held with hands while at work.[br /]
[br /]
Where there is a will, there is a way. Despite being almost an illiterate person, Leeuwenhoek had a keen insight and passion to contribute something ‘unique’ in the field of science. To quench his thirst for knowledge, he began to spend much time on his hobby, devising different kinds of lenses. He made many lenses, one after another and his each new lens would be better than the previous one. Grinding lenses and using them to study tiny objects became a favorite hobby of his.[br /]
[br /]
As time passed, he became the father of five children. Unfortunately, four of them died young. The only surviving child was his daughter Maria, who looked after her father until his last breath. Later in 1671, Leeuwenhoek married Cornelia Swalmius. His second marriage lasted for 23 years, till the death of Cornelia in 1694. This is all that accounts for his marriage life that’s available today.[br /]
[br /]
[b]Revealing a ‘ New World’[/b][br /]
[br /]
In 1668, Leeuwenhoek went to London, the only visit of his lifetime. At this point of time, he seems to have been inspired to take up microscopy from the illustrated book Micrographia, which was written by Robert Hooke, a well-known microscopist. It depicted Hooke’s own observations with the microscope that was a ‘rage’ at the time. Leeuwenhoek was attracted to see the book because number of pictures relating to textiles were placed inside. This would definitely be useful to any cloth merchant.
[br /]
[br /]
It has been said that Leeuwenhoek started examination of minerals from the cliffs of Gravesend and Rochester. According to authorized references available, Leeuwenhoek began to construct microscopes only after 1670. In his spare time, he would make magnifying glasses. He was known to have made around 400 to 500 lenses (the figure is debatable). The smallest amongst them had a diameter of less than 1/8th inch. As he was engrossed in the study, he became fascinated with this new subject, microbiology.[br /]
[br /]
After sustained efforts, he was able to make a simple microscope with one lens, having about half the diameter of a pea. Even this skilful ‘artist’ had made himself a delicate but long-lasting stand for holding his tiny lenses. His microscope was much better than the early compound ones, as the specimens were seen with much clarity and magnification.[br /]
[br /]
At one side, his contemporary astronomer Galileo Galilei was busy in revealing the mysteries of the sky with his ‘brainchild’ telescope, whereas on the other side, Leeuwenhoek was engrossed in microscopic studies, setting his eyes on the world of invisibles. Whatever he found around himself, he would put it under the lens of his microscope and begin examining it. He continued studying specimens like the hair of animals, feet or head of the flea, specimen’s skin, and so on.[br /]
[br /]
According to his neighbors, these were signs of madness because Leeuwenhoek would stick to his microscope for hours, without having even a drop of water ![br /]
[br /]
The people of Delft soon began to criticize Leeuwenhoek, but their comments could not deter him from achieving his goal. Through his wonderful instrument – microscope, he was wandering in a unique mysterious world. His each new day would end with a new mystery unraveled and unrivalled.[br /]
[br /]
Meanwhile, a friend of Leeuwenhoek put him in touch with the Royal Society of London to which, he would communicate through letters describing his discoveries, in the coming years.[br /]
[br /]
In April 1673, he sent his first letter to the Royal Society describing his unique observations of the mouthparts and stings of a bee, a human louse and fungus. A letter addressed to Henry Oldenburg, secretary of the Royal Society, revealed that "a certain most ingenious person here Leeuwenhoek has devised microscopes, which far surpasses those, manufactured by others." This letter was published in the Philosophical Transactions of the Society. This was the first of the around 165 letters describing Leeuwenhoek’s observations, published in the Transactions during the next 50 years of that time. He reported all his work in Dutch, which was later translated and published in Latin or English.[br /]
[br /]
[b]‘Little Creatures’ in the Rain Water[/b][br /]
[br /]
In the ensuing period, Leeuwenhoek continued making microscopes having better quality than the previous one and observing various specimens, under it.[br /]
[br /]
One rainy day, Leeuwenhoek was busy in his microscopic studies. Taking a break from work as the rains had stopped, he went out for a stroll. Suddenly, one frog jumped out from a puddle that caught Leeuwenhoek’s attention towards the rainwater and resided into that puddle. A thought struck in his mind and he collected the rainwater for microscopic examination. He then put one drop under the lens of microscope, and began observing the sample.[br /]
[br /]
It was amazing ! There were number of lives swimming in just one drop of water ! These ‘little creatures’ were invisible to naked eyes. Leeuwenhoek called these one-celled animals as animalcules or ‘wretched beastis’, which are known as protozoa today. They were estimated to be some 10,000 times smaller than water fleas. He also saw the filaments of algae in the water sample.[br /]
[br /]
In a letter dated September 7, 1674, he gave an excellent description of the green algae Spirogyra, found in the lake water :[br /]
[br /]
"Passing just lately over this lake, … and examining this water next day, I found floating therein diverse earthly particles, and some green streaks, spirally wound serpent-wise, and orderly arranged, after the manner of the copper or tin worms, which distillers use to cool their liquors as they distil over. The whole circumference of each of these streaks was about the thickness of a hair of one’s head… all consisted of very small green globules joined together : and there were very many small green globules as well."[br /]
[br /]
[b]Next Hunt : Bacteria[/b][br /]
[br /]
His first discovery led him to a new idea of the profusion of the nature. He began examining pepper to ensure if its heat was caused by spikes. For this, he put peppercorns in water and let it in his study-room to soften for three weeks. It was topped up with snow-water. On April 24, 1676, when he was examining the water, he was surprised to see tiny organisms moving in the water specimen ! It was the first bacteria ever observed by man.[br /]
[br /]
In a letter addressed to the Royal Society, he described these organisms as :[br /]
[br /]
"…the 4th sort of creatures, which drifted among the three sorts aforesaid, were incredibly small, nay so small, in my sight, that I judged that even if 100 of these very wee animals lay stretched out one against another, they could not reach to the length of a grain of coarse sand; and if this be true, then ten thousand of these living creatures could scarce equal the bulk of a coarse sand-grain…"[br /]
[br /]
The members of the Society were stunned reading the letter. Who was this man – a scientist or a sci-fi writer ? Much doubt was created regarding his observations, not only in London but also in Leeuwenhoek’s native Delft. The jurists, medical fraternity and the English community set up a vigorous campaign to confirm if Leeuwenhoek’s discoveries were based on true observations.[br /]
[br /]
The Royal Society wrote a letter asking him if he would rent his microscope for few days. But Leeuwenhoek did not send his ‘loving’ instrument. To confirm Leeuwenhoek’s reports, the Society appointed two scientists – Nehemiah Grew, the plant anatomist and Robert Hooke, the microscopist. They attempted to validate Leeuwenhoek’s observations. First time they failed, casting doubts on his report. However, Hooke again tried using a microscope with 330 X (power of magnification) and confirmed Leeuwenhoek’s success. Both scientists confirmed that their observations were similar to those described in the letters by Leeuwenhoek.[br /]
[br /]
Now, the Royal Society accepted Leeuwenhoek as a scientist and declared him as the discoverer of bacteria.[br /]
[br /]
Leeuwenhoek continued working in this direction and observed different kinds of bacteria, isolated from different sources such as rainwater, pure water, pond water, human saliva and also extracts from human intestine. He also drew and calculated their sizes. Leeuwenhoek studied even his own faeces and noted that ‘when of ordinary thickness’, no animalcules were observed but whenever ‘the stuff was a bit looser than ordinary I have seen animalcules therein.’ Though he described his observations very well, he could not explain as to what they were actually.[br /]
[br /]
So, the first representation of bacteria found mention in the Royal Society’s publication, Philosophical Transactions in 1683.[br /]
[br /]
[b]Delved Into Researches[/b][br /]
[br /]
Stephen Hamm, a student from Leyden, drew Leeuwenhoek’s attention towards a new field. He had marked the presence of spermatozoa in the semen of a man suffering from veneral disease. According to Hamm, it was a symptom of corruption. Whereas, Leeuwenhoek thought spermatozoa were the part of normal semen. After an experiment he ‘performed without defiling’ himself, and reported his observations to the Royal Society in November. He requested the President of the Society not to put his letter in public believing it would create disquiet. However, the members of the society were less squeamish and so they decided to publish Leeuwenhoek’s letter in 1678. Now, he was considered as the first person to describe the spermatozoa from insects, dogs and man, whereas, Stephen Hamm was honored as a co-discoverer.[br /]
[br /]
According to Leeuwenhoek, the discovery of spermatozoa was one of the most important discoveries in his life.[br /]
[br /]
[b]Opposing Superstition[/b][br /]
[br /]
Leeuwenhoek was living in the age of superstition. People believed that certain forms of life like flea, came from air, mud, water or decaying material. It was a general belief prevailing in those days that life could arise out of nothing. Leeuwenhoek wanted to break such superstitions. After several experiments, he concluded that all forms of life, even the lowest, must have a parent.[br /]
[br /]
His further biological observations included the 1684 description of red blood cells. For this, he cut his finger and put a drop of his own blood under the microscope. He described and estimated the red blood cells to be 25,000 times smaller than a fine grain of sand. He also observed the tail of a tadpole through a microscope and could see the blood circulation in the blood vessels.[br /]
[br /]
The list of his discoveries went on and on. He became famous as more of his letters covering his works began to get published and translated. The Royal Society of England elected him a Fellow of the Society in 1680. Now, Leeuwenhoek joined other scientific luminaries of his days, like Robert Hooke, Henry Oldenburg, Christopher Wren and Robert Boyle. It would be interesting to know and note that he never attended any meeting of the society ![br /]
[br /]
As Leeuwenhoek’s fame spread all over the world, the Queen of England and the Tsar, Peter the Great of Russia came to him to satisfy their curiosity, visualizing the ‘micro’ world through his ‘magic’ microscope. Leeuwenhoek demonstrated circulation in the capillaries of an eel to the Tsar in 1698. The dramatic nature of his discoveries attracted many other notable personalities to visit him, including Peter I the Great of Russia, James II of England and Frederick II the Great, of Prussia.[br /]
[br /]
[b]In His Last Days[/b][br /]
[br /]
Leeuwenhoek enjoyed good health till the very end of his life. He continued playing with his wonderful instrument – microscope and making notes of his observations, until the last days of his life. The man, who dedicated his entire life in searching new horizons of biology, left earth peacefully on August 26, 1723. He died at the age of 90 years, 10 months and 2 days. His last few letters to the Royal Society described that Leeuwenhoek was suffering from a rare disease generally found in sheep and oxen. He caught the disease, signaling the uncontrollable movement of the diaphragm, while studying the bacteria. It is renamed as ‘Van Leeuwenhoek’ disease.[br /]
[br /]
Upon his death, the pastor of the New Church at Delft sent a letter addressing the Royal Society :[br /]
[br /]
"….Antony Van Leeuwenhoek considered that what is true in natural philosophy can be most fruitfully investigated by the experimental method, supported by the evidence of the senses, for which reason, by diligence and tireless labor he made with his own hand certain most excellent lenses, with the aid of which he discovered many secrets of Nature, now famous throughout the whole philosophical world."[br /]
[br /]
This great ‘philosopher’ (ancient meaning of scientist) was finally laid to rest at Oude Kert at Delft, where an obelisk bearing his portrait was raised by his daughter. An epitaph with a poem inscribed in his honor by Hubert Korneliszaon Poot read :[br /]
[br /]
Have each in every walk of life,
Respect for ripe and noble age
and wondrous gifts,
then tread softly here :
For in this place in Leeuwenhoek
Grey science is put to rest.[br /]
[br /]
[br /]
[br /]
In the first paragraph of the letter, the humble shopkeeper had written about his health and wished for the well-being of the society members. Mentioning about his neighbors, he described their superstitions. The members poked fun at him while it was being read. Suddenly, everyone stopped laughing. Astonishment and awe clearly lit on their faces. All eyes stuck on a title at the beginning of the next paragraph. The title read :[br /]
[br /]
Some unique specimen observed under the microscope constructed by Mr. Leeuwenhoek displaying skin cells.[br /]
[br /]
It was surprising ! They studied the whole letter calmly with interest. In the end, the members unanimously concluded that an almost illiterate Dutch shopkeeper had certainly discovered new kind of ‘creatures’.[br /]
[br /]
In return, they sent an appreciation letter to the shopkeeper, encouraging him to continue his experiments in the chosen direction. As a result, the Royal Society of London got around 165 (the figure is debatable) worthy letters from the Dutchman Antonie Van Leeuwenhoek, in the next 50 years. These letters brought a revolutionary change in the field of science, opening a new vista, of Microbiology.[br /]
[br /]
[b]Early Years[/b][br /]
[br /]
Little is known of Leeuwenhoek’s early life. Born on October 24, 1632, at Delft city of Holland [Netherlands], the Leeuwenhoeks, were not a well-to-do family. Although they had maintained their position in the society, the trades adopted were making and selling bamboo baskets and liquor.[br /]
[br /]
Antonie’s family name ‘Leeuw-en-hoek’ is often quite difficult to spell for non-Dutch people. The pronunciation ‘layu-wen-hook’ is a passable English approximation. It is said to be concerned with the location of his house situated at the corner (hoek) of the Lion’s (Leeuw) gate in the Delft City, then. Whether there was a tradition of deriving the family name from the local place or not, is still uncertain.[br /]
[br /]
Antonie’s father, Philips Leeuwenhoek was a basket-maker by profession and his mother, Margaretha Bel van den Berch belonged to a family of beer brewers. Antonie lost his father at the age of five. His mother Margaretha remarried Jacob Molijn, a painter and also a bailiff, after a three-year span.[br /]
[br /]
[b]Teenage Years[/b][br /]
[br /]
Antonie received little education at the town of Warmond during his early years. But he didn’t get exposure to the scientific knowledge of that time. Whatever little education he had, it was in his mother tongue – Dutch and he never had the opportunity to learn second language.[br /]
[br /]
In those days, Latin was considered the scientific language and most of the scientific works were available in Latin only. As Leeuwenhoek didn’t know Latin, he was unaware of the works of other scientists.[br /]
[br /]
Antonie spent some of his teenage years at Benthuizen with his uncle. During that period, his stepfather died in 1648. Now, Antonie was left to fend for himself. Soon, he got a job as an apprentice to a textile merchant William Davidson, in Amsterdam.[br /]
[br /]
Antonie aged 16, packed off his bags for the big city of Amsterdam leaving behind memories of his birthplace Delft – the lovely city breathing in the rippling sound of the water flowing through canals, and the beautiful view of the windmills under the blue sky.[br /]
[br /]
[b]Hobby Becomes Habit[/b][br /]
[br /]
During his five-year stay at Amsterdam, Leeuwenhoek sat at the Cloth Worker’s Guild examination. Generally, it took 3 years to pass the exams, but Leeuwenhoek took only 6 weeks ! At this point of time, Leeuwenhoek was introduced to magnifying glasses that were used to count thread density.[br /]
[br /]
When he was 21, he decided to spend the rest of his life at his native place. Returning to Delft, he bought a house at the Hippolytusburt, also called as ‘The Golden Head’, and opened a small shop there. Leeuwenhoek set himself up in business as a draper (a fabric merchant) and haberdasher. He married Barbara de Mey, daughter of a silk merchant. Meanwhile, he also worked as a surveyor and a wine assayer.[br /]
[br /]
Four years after opening the shop, Leeuwenhoek obtained a post of minor civic official that was ‘a position as chamberlain to the sheriffs of Delft’. His duties included sweeping the council room, arranging the decor, lighting the fire ‘at the proper time’ and also ‘preserving any coal that might be left unconsumed. ’Though his position was as the main servant of Delft Town Council that was of lower category, he used to conduct his duties diligently. He was not a rich person, but the two important characteristics of his nature were the best in itself – curiosity and enthusiasm.[br /]
[br /]
In his days, ordinary lenses were used for magnifying the tiny object and the best use then of it was to estimate the correct density of the fabric strand, of which, he was quite conversant with. It was not much remarkable and had to be held with hands while at work.[br /]
[br /]
Where there is a will, there is a way. Despite being almost an illiterate person, Leeuwenhoek had a keen insight and passion to contribute something ‘unique’ in the field of science. To quench his thirst for knowledge, he began to spend much time on his hobby, devising different kinds of lenses. He made many lenses, one after another and his each new lens would be better than the previous one. Grinding lenses and using them to study tiny objects became a favorite hobby of his.[br /]
[br /]
As time passed, he became the father of five children. Unfortunately, four of them died young. The only surviving child was his daughter Maria, who looked after her father until his last breath. Later in 1671, Leeuwenhoek married Cornelia Swalmius. His second marriage lasted for 23 years, till the death of Cornelia in 1694. This is all that accounts for his marriage life that’s available today.[br /]
[br /]
[b]Revealing a ‘ New World’[/b][br /]
[br /]
In 1668, Leeuwenhoek went to London, the only visit of his lifetime. At this point of time, he seems to have been inspired to take up microscopy from the illustrated book Micrographia, which was written by Robert Hooke, a well-known microscopist. It depicted Hooke’s own observations with the microscope that was a ‘rage’ at the time. Leeuwenhoek was attracted to see the book because number of pictures relating to textiles were placed inside. This would definitely be useful to any cloth merchant.
[br /]
[br /]
It has been said that Leeuwenhoek started examination of minerals from the cliffs of Gravesend and Rochester. According to authorized references available, Leeuwenhoek began to construct microscopes only after 1670. In his spare time, he would make magnifying glasses. He was known to have made around 400 to 500 lenses (the figure is debatable). The smallest amongst them had a diameter of less than 1/8th inch. As he was engrossed in the study, he became fascinated with this new subject, microbiology.[br /]
[br /]
After sustained efforts, he was able to make a simple microscope with one lens, having about half the diameter of a pea. Even this skilful ‘artist’ had made himself a delicate but long-lasting stand for holding his tiny lenses. His microscope was much better than the early compound ones, as the specimens were seen with much clarity and magnification.[br /]
[br /]
At one side, his contemporary astronomer Galileo Galilei was busy in revealing the mysteries of the sky with his ‘brainchild’ telescope, whereas on the other side, Leeuwenhoek was engrossed in microscopic studies, setting his eyes on the world of invisibles. Whatever he found around himself, he would put it under the lens of his microscope and begin examining it. He continued studying specimens like the hair of animals, feet or head of the flea, specimen’s skin, and so on.[br /]
[br /]
According to his neighbors, these were signs of madness because Leeuwenhoek would stick to his microscope for hours, without having even a drop of water ![br /]
[br /]
The people of Delft soon began to criticize Leeuwenhoek, but their comments could not deter him from achieving his goal. Through his wonderful instrument – microscope, he was wandering in a unique mysterious world. His each new day would end with a new mystery unraveled and unrivalled.[br /]
[br /]
Meanwhile, a friend of Leeuwenhoek put him in touch with the Royal Society of London to which, he would communicate through letters describing his discoveries, in the coming years.[br /]
[br /]
In April 1673, he sent his first letter to the Royal Society describing his unique observations of the mouthparts and stings of a bee, a human louse and fungus. A letter addressed to Henry Oldenburg, secretary of the Royal Society, revealed that "a certain most ingenious person here Leeuwenhoek has devised microscopes, which far surpasses those, manufactured by others." This letter was published in the Philosophical Transactions of the Society. This was the first of the around 165 letters describing Leeuwenhoek’s observations, published in the Transactions during the next 50 years of that time. He reported all his work in Dutch, which was later translated and published in Latin or English.[br /]
[br /]
[b]‘Little Creatures’ in the Rain Water[/b][br /]
[br /]
In the ensuing period, Leeuwenhoek continued making microscopes having better quality than the previous one and observing various specimens, under it.[br /]
[br /]
One rainy day, Leeuwenhoek was busy in his microscopic studies. Taking a break from work as the rains had stopped, he went out for a stroll. Suddenly, one frog jumped out from a puddle that caught Leeuwenhoek’s attention towards the rainwater and resided into that puddle. A thought struck in his mind and he collected the rainwater for microscopic examination. He then put one drop under the lens of microscope, and began observing the sample.[br /]
[br /]
It was amazing ! There were number of lives swimming in just one drop of water ! These ‘little creatures’ were invisible to naked eyes. Leeuwenhoek called these one-celled animals as animalcules or ‘wretched beastis’, which are known as protozoa today. They were estimated to be some 10,000 times smaller than water fleas. He also saw the filaments of algae in the water sample.[br /]
[br /]
In a letter dated September 7, 1674, he gave an excellent description of the green algae Spirogyra, found in the lake water :[br /]
[br /]
"Passing just lately over this lake, … and examining this water next day, I found floating therein diverse earthly particles, and some green streaks, spirally wound serpent-wise, and orderly arranged, after the manner of the copper or tin worms, which distillers use to cool their liquors as they distil over. The whole circumference of each of these streaks was about the thickness of a hair of one’s head… all consisted of very small green globules joined together : and there were very many small green globules as well."[br /]
[br /]
[b]Next Hunt : Bacteria[/b][br /]
[br /]
His first discovery led him to a new idea of the profusion of the nature. He began examining pepper to ensure if its heat was caused by spikes. For this, he put peppercorns in water and let it in his study-room to soften for three weeks. It was topped up with snow-water. On April 24, 1676, when he was examining the water, he was surprised to see tiny organisms moving in the water specimen ! It was the first bacteria ever observed by man.[br /]
[br /]
In a letter addressed to the Royal Society, he described these organisms as :[br /]
[br /]
"…the 4th sort of creatures, which drifted among the three sorts aforesaid, were incredibly small, nay so small, in my sight, that I judged that even if 100 of these very wee animals lay stretched out one against another, they could not reach to the length of a grain of coarse sand; and if this be true, then ten thousand of these living creatures could scarce equal the bulk of a coarse sand-grain…"[br /]
[br /]
The members of the Society were stunned reading the letter. Who was this man – a scientist or a sci-fi writer ? Much doubt was created regarding his observations, not only in London but also in Leeuwenhoek’s native Delft. The jurists, medical fraternity and the English community set up a vigorous campaign to confirm if Leeuwenhoek’s discoveries were based on true observations.[br /]
[br /]
The Royal Society wrote a letter asking him if he would rent his microscope for few days. But Leeuwenhoek did not send his ‘loving’ instrument. To confirm Leeuwenhoek’s reports, the Society appointed two scientists – Nehemiah Grew, the plant anatomist and Robert Hooke, the microscopist. They attempted to validate Leeuwenhoek’s observations. First time they failed, casting doubts on his report. However, Hooke again tried using a microscope with 330 X (power of magnification) and confirmed Leeuwenhoek’s success. Both scientists confirmed that their observations were similar to those described in the letters by Leeuwenhoek.[br /]
[br /]
Now, the Royal Society accepted Leeuwenhoek as a scientist and declared him as the discoverer of bacteria.[br /]
[br /]
Leeuwenhoek continued working in this direction and observed different kinds of bacteria, isolated from different sources such as rainwater, pure water, pond water, human saliva and also extracts from human intestine. He also drew and calculated their sizes. Leeuwenhoek studied even his own faeces and noted that ‘when of ordinary thickness’, no animalcules were observed but whenever ‘the stuff was a bit looser than ordinary I have seen animalcules therein.’ Though he described his observations very well, he could not explain as to what they were actually.[br /]
[br /]
So, the first representation of bacteria found mention in the Royal Society’s publication, Philosophical Transactions in 1683.[br /]
[br /]
[b]Delved Into Researches[/b][br /]
[br /]
Stephen Hamm, a student from Leyden, drew Leeuwenhoek’s attention towards a new field. He had marked the presence of spermatozoa in the semen of a man suffering from veneral disease. According to Hamm, it was a symptom of corruption. Whereas, Leeuwenhoek thought spermatozoa were the part of normal semen. After an experiment he ‘performed without defiling’ himself, and reported his observations to the Royal Society in November. He requested the President of the Society not to put his letter in public believing it would create disquiet. However, the members of the society were less squeamish and so they decided to publish Leeuwenhoek’s letter in 1678. Now, he was considered as the first person to describe the spermatozoa from insects, dogs and man, whereas, Stephen Hamm was honored as a co-discoverer.[br /]
[br /]
According to Leeuwenhoek, the discovery of spermatozoa was one of the most important discoveries in his life.[br /]
[br /]
[b]Opposing Superstition[/b][br /]
[br /]
Leeuwenhoek was living in the age of superstition. People believed that certain forms of life like flea, came from air, mud, water or decaying material. It was a general belief prevailing in those days that life could arise out of nothing. Leeuwenhoek wanted to break such superstitions. After several experiments, he concluded that all forms of life, even the lowest, must have a parent.[br /]
[br /]
His further biological observations included the 1684 description of red blood cells. For this, he cut his finger and put a drop of his own blood under the microscope. He described and estimated the red blood cells to be 25,000 times smaller than a fine grain of sand. He also observed the tail of a tadpole through a microscope and could see the blood circulation in the blood vessels.[br /]
[br /]
The list of his discoveries went on and on. He became famous as more of his letters covering his works began to get published and translated. The Royal Society of England elected him a Fellow of the Society in 1680. Now, Leeuwenhoek joined other scientific luminaries of his days, like Robert Hooke, Henry Oldenburg, Christopher Wren and Robert Boyle. It would be interesting to know and note that he never attended any meeting of the society ![br /]
[br /]
As Leeuwenhoek’s fame spread all over the world, the Queen of England and the Tsar, Peter the Great of Russia came to him to satisfy their curiosity, visualizing the ‘micro’ world through his ‘magic’ microscope. Leeuwenhoek demonstrated circulation in the capillaries of an eel to the Tsar in 1698. The dramatic nature of his discoveries attracted many other notable personalities to visit him, including Peter I the Great of Russia, James II of England and Frederick II the Great, of Prussia.[br /]
[br /]
[b]In His Last Days[/b][br /]
[br /]
Leeuwenhoek enjoyed good health till the very end of his life. He continued playing with his wonderful instrument – microscope and making notes of his observations, until the last days of his life. The man, who dedicated his entire life in searching new horizons of biology, left earth peacefully on August 26, 1723. He died at the age of 90 years, 10 months and 2 days. His last few letters to the Royal Society described that Leeuwenhoek was suffering from a rare disease generally found in sheep and oxen. He caught the disease, signaling the uncontrollable movement of the diaphragm, while studying the bacteria. It is renamed as ‘Van Leeuwenhoek’ disease.[br /]
[br /]
Upon his death, the pastor of the New Church at Delft sent a letter addressing the Royal Society :[br /]
[br /]
"….Antony Van Leeuwenhoek considered that what is true in natural philosophy can be most fruitfully investigated by the experimental method, supported by the evidence of the senses, for which reason, by diligence and tireless labor he made with his own hand certain most excellent lenses, with the aid of which he discovered many secrets of Nature, now famous throughout the whole philosophical world."[br /]
[br /]
This great ‘philosopher’ (ancient meaning of scientist) was finally laid to rest at Oude Kert at Delft, where an obelisk bearing his portrait was raised by his daughter. An epitaph with a poem inscribed in his honor by Hubert Korneliszaon Poot read :[br /]
[br /]
Have each in every walk of life,
Respect for ripe and noble age
and wondrous gifts,
then tread softly here :
For in this place in Leeuwenhoek
Grey science is put to rest.[br /]
[br /]
[br /]
We are humans. We have minds, books and records to develop our knowledge and intellect. What we have discovered so far is nomean achievement. Our aim is similar to Tennyson’s Ulysses :[br /]
[br /]
[i]To follow knowledge like a sinking star[br /]
Beyond the utmost bounds of human thought[/i]
[br /]
[br /]
In the 17th century, was born, a man who followed the path of knowledge overcoming hurdles, to reach the top, with hardly any academic background ! He was Antonie Van Leeuwenhoek, a Dutch microscopist, who introduced us to the vision of a New World – the world of invisibles. He made around 500 simple microscopes, far better than the previous compound ones, with primitive equipments. He neither knew Latin nor English. He never wrote a research paper in his life. Despite lack of such endowments, he is considered The Father of Microbiology, as he discovered the first microorganism. He made a series of discoveries, based on his microscopic observations, relating to various fields of biology, like human histology, entomology, embryology and botany. He instituted new branches of biology – Bacteriology and Protozoology.[br /]
[br /]
His worthy inventions and researches played a vital role during the scientific revolution of that era. The life of this great ‘layman’ was concentrated on unraveling the mystery of microorganisms.[br /]
[br /]
[br /]
[br /]
[i]To follow knowledge like a sinking star[br /]
Beyond the utmost bounds of human thought[/i]
[br /]
[br /]
In the 17th century, was born, a man who followed the path of knowledge overcoming hurdles, to reach the top, with hardly any academic background ! He was Antonie Van Leeuwenhoek, a Dutch microscopist, who introduced us to the vision of a New World – the world of invisibles. He made around 500 simple microscopes, far better than the previous compound ones, with primitive equipments. He neither knew Latin nor English. He never wrote a research paper in his life. Despite lack of such endowments, he is considered The Father of Microbiology, as he discovered the first microorganism. He made a series of discoveries, based on his microscopic observations, relating to various fields of biology, like human histology, entomology, embryology and botany. He instituted new branches of biology – Bacteriology and Protozoology.[br /]
[br /]
His worthy inventions and researches played a vital role during the scientific revolution of that era. The life of this great ‘layman’ was concentrated on unraveling the mystery of microorganisms.[br /]
[br /]
[br /]
[b]October 24, 1632[/b] Birth of Antonie Van Leeuwenhoek in Delft, Netherlands.[br /]
[br /]
[b]1648[/b] Went to Amsterdam. Joined the firm of the Scottish textile merchant William Davidson as an apprentice.[br /]
[br /]
[b]1651[/b] Developed a simple microscope.[br /]
[br /]
[b]1654[/b] Returned to Delft.Married Barbara de Mey. Opened his own business as a draper.[br /]
[br /]
[b]1660[/b] Appointed a Chamberlain to the Sheriffs of Delft.[br /]
[br /]
[b]1668[/b] Went to London. Inspired by Robert ‘Hooke’s Micrographia, IInd Edition.’[br /]
[br /]
[b]1671[/b] Started working on microscopes.[br /]
[br /]
[b]April 1673[/b] His first ever observations were published in Philosophical Transaction by the Royal Society of London.[br /]
[br /]
[b]September 1674[/b] Discovery of microorganisms including bacteria and protozoa. He described them as very little animalcules.[br /]
[br /]
[b]November 1677[/b] Discovery of Spermatozoa.[br /]
[br /]
[b]1680[/b] Elected a Fellow of the Royal Society of London.[br /]
[br /]
[b]1683[/b] Represented the first drawings of Bacteria.[br /]
[br /]
[b]1684[/b] Gave the first accurate description of RBCs [Red Blood Cells].[br /]
[br /]
[b]August 26, 1723[/b] Died in Delft, Netherlands.[br /]
[br /]
[br /]
[br /]
[b]1648[/b] Went to Amsterdam. Joined the firm of the Scottish textile merchant William Davidson as an apprentice.[br /]
[br /]
[b]1651[/b] Developed a simple microscope.[br /]
[br /]
[b]1654[/b] Returned to Delft.Married Barbara de Mey. Opened his own business as a draper.[br /]
[br /]
[b]1660[/b] Appointed a Chamberlain to the Sheriffs of Delft.[br /]
[br /]
[b]1668[/b] Went to London. Inspired by Robert ‘Hooke’s Micrographia, IInd Edition.’[br /]
[br /]
[b]1671[/b] Started working on microscopes.[br /]
[br /]
[b]April 1673[/b] His first ever observations were published in Philosophical Transaction by the Royal Society of London.[br /]
[br /]
[b]September 1674[/b] Discovery of microorganisms including bacteria and protozoa. He described them as very little animalcules.[br /]
[br /]
[b]November 1677[/b] Discovery of Spermatozoa.[br /]
[br /]
[b]1680[/b] Elected a Fellow of the Royal Society of London.[br /]
[br /]
[b]1683[/b] Represented the first drawings of Bacteria.[br /]
[br /]
[b]1684[/b] Gave the first accurate description of RBCs [Red Blood Cells].[br /]
[br /]
[b]August 26, 1723[/b] Died in Delft, Netherlands.[br /]
[br /]
[br /]
"…my work, which I’ve done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men. And there withal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof."[br /]
[br /]
- Antonie Van Leeuwenhoek[br /]
[br /]
[June 12, 1716][br /]
[br /]
One of the most imperfectly understood figures in the origins of experimental biology, Leeuwenhoek’s working manner that was essentially crude and undisciplined. He used those methods, which were untried before. His methods of investigation were lacking in refinement and objectivity. When he entered into the world of observational microscopy, he was unknowingly following the path of some well-known predecessors from different fields.[br /]
[br /]
Leeuwenhoek entered the field of science as a dwarf, where many giants were reigning over various branches. The new application of magnifying glasses and compound microscopes to biological studies in the mid-seventieth century was the most important factor in the subsequent development of the anatomical research. Primitive early microscopes enabled Robert Hooke to first observe the small compartments in the plants called cells and in the field of Histology, Malpighi to describe capillary circulation in the lungs, in 1661. Apart from it, with Swammerdam, he had revealed newer truths in the field of Anatomy in 1669. Insect morphology was described very well by Power in 1664 and by Robert Hooke in 1665. In Botany, a new branch of Plant Histology was developed by Grew in 1672 and by Malpighi in 1675.[br /]
[br /]
These scientists confined themselves largely to microscopic investigation with some small degree of preparative technique, i.e. the dissection of material. Leeuwenhoek entered the field with purely observational microscopy. It is noteworthy that he did not start his microscopic observations seriously until he was 40. His active period could be considered from 1673 to 1723.[br /]
[br /]
Documentary evidence of Leeuwenhoek’s works is found in the form of letters in which he recorded his observations. The bulk of his letters are preserved at the Royal Society’s rooms in Carlton House Terrace in London. The manuscript of his first letter sent in 1673 is lost, which appeared in Philosophical Transactions.[br /]
[br /]
[b]Making Of Microscopes[/b][br /]
[br /]
Building microscopes started as a hobby for Leeuwenhoek. He developed a way to grind tiny, high quality and high-power lenses. But his method of making the lenses was kept secret, so that there was no tradition left behind after him.[br /]
[br /]
A recent study has revealed that some of the lenses might have been made by grinding, while the best ones were blown. When a glass bulb is blown, a small drop of thickened glass forms at the bottom of the bulb. It is much like a drop sits at the bottom of the blown up soap bubble. Leeuwenhoek learned the method and by breaking away the excess glass carefully, he could get these crystallized small drops to be used as a lens. Then he devised a counter that allowed him to count the number of ‘minute creatures’ in a very small quantity of specimen, and then calculate numbers in the larger volume.[br /]
[br /]
He made microscopes using these lenses, with a purpose to view certain objects. In total he had around 500 lenses with the magnifying power between 50 and 300 times.[br /]
[br /]
His microscopes were simple instruments with a single small lens clamped between two metal plates. The object was placed on a fine pin and its distance from the plates adjusted by turning a screw. The entire instrument was 3 to 4 inches long. It had to be held up close to the eye, requiring good lighting and great patience when at use.[br /]
[br /]
A number of microscopes were auctioned and dispersed in 1747. Some 26 microscopes, complete with objects, were presented to the Royal Society. Two years after Leeuwenhoek’s death, most of his microscopes disappeared. Of these, only nine priceless microscopes, mounted in silver, are kept in the museum’s safe and their replica is on display for the public.[br /]
[br /]
[b]Discovery of Microorganisms[/b][br /]
[br /]
In 1673, Leeuwenhoek began writing a series of letters to the Royal Society of London, describing his microscopic observations. The first ever recorded letter contained some observations including mouth parts of fleas and stings of bees. It was translated into English and Latin and published in the Philosophical Transactions of the Royal Society.[br /]
[br /]
Leeuwenhoek, inspired by the appreciation, began to find out new organisms and their parts. In September of 1674, he observed the first microorganisms ever seen by a man, in the drop of puddle water !Beginning in 1676, he wrote around 30 letters to the Royal Society in London, describing the microorganisms termed by him as animalcules. They are now classified as protozoa, bacteria and rotifers.[br /]
[br /]
He classified the microorganisms found in what he called Little Animals in Rain Water. It was the first bacteria ever observed by man. His description read :[br /]
[br /]
"There was a fourth sort, which were so small that I was not able to give them any figure at all. These were a thousand times smaller than the eye of a large louse. These exceeded all the former in celerity. I have often observed them to stand still as it were on a point and then turn themselves about with that swiftness, as we see a top turn round, the circumference they made being no larger than that of a grain of small sand, and then extending themselves straight forward, and by and by lying in a bending posture. I discovered also several other sorts of animals; these were generally made up of such soft parts, as the former, that they burst asunder as soon as they came to want water."[br /]
[br /]
In his observations on rotifers in 1702, he remarked :[br /]
[br /]
"In all falling rain, carried from gutters into water-butts, animalcules are to be found; and that in all kinds of water, standing in the open air, animalcules can turn up. For these animalcules can be carried over by the wind, along with the bits of dust floating in the air."[br /]
[br /]
In a letter dated December 25, 1702, Leeuwenhoek gave descriptions of protists. It was large group comprising mostly single cell organisms such as protozoa, simple algae and fungi, slime moulds and the bacteria. There was a description of ciliates, which is a large group of advanced protozoans, including the ciliate Vorticella :[br /]
[br /]
"In structure these little animals were fashioned like a bell, and at the round opening they made such a stir, that the particles in the water thereabout were set in motion thereby…. And though I must have seen quite 20 of these little animals on their long tails alongside one other very gently moving, with outstretched bodies and straightened our tails; yet in an instant, as it were, they pulled their bodies and their tails together, and no sooner had they contracted their bodies and tails, than they began to stick their tails out again very leisurely, and stayed thus some time continuing their gentle motion : which sight I found mightily diverting."[br /]
[br /]
The first observations on living bacteria ever recorded, is found in the letter dated September 17, 1683. In this, he wrote to the Royal Society about his observations on the plaque between his own teeth. He repeated these observations on two ladies, probably his own wife and daughter. His description read :[br /]
[br /]
"I then most always saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving. The biggest sort… had a very strong and swift motion, and shot through the water (or spittle) like a pike does through the water. The second sort… oft-times spun round like a top…and these were far more in number."[br /]
[br /]
He also studied teeth of two old men who had never cleaned their teeth. In the mouth of one of those old men, Leeuwenhoek observed:[br /]
[br /]
"…an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time. The biggest sort… bent their body into curves in going forwards…. Moreover, the other animalcules were in such enormous numbers, that all the water… seemed to be alive."[br /]
[br /]
[b]Discovery of Spermatozoa[/b][br /]
[br /]
In the 17th and 18th centuries, no scientific problem was more laden with religious and philosophical overtones than the problem of generation. The problem was regarding how a mechanistic nature, devoid of spirit, could generate the purposeful complexity of living organisms, including human beings. Leeuwenhoek did not believed in the ‘theory of spontaneous generation’, prevailing in those days. Such theories asserted that the flea was produced from sand, others from dust and other such things. But Leeuwenhoek proved that it bred in the regular way to winged insects.[br /]
[br /]
John Ham, a student from the medical school at Leiden, brought him ‘the spontaneously discharged semen of a man who had lain with an unclean woman and was suffering from gonorrhea’, in which Ham himself had found ‘small animals with tails’. Leeuwenhoek also studied it and observed such ‘little animals’ within, which he called animalcula in semine masculino (animalcules in human semen). They had tails and could be alive for a few hours only. Now, he resumed observations of his own semen acquired, ‘not by sinfully defiling himself but as a natural consequence of conjugal coitus’. He observed a multitude of ‘animalcules’, less than a millionth the size of a coarse grain of sand and with thin, undulating transparent tails, which we know today as spermatozoa.[br /]
[br /]
He continued examining the semen specimen of birds, frogs, insects, cattle and several other species. He described these observations in a brief letter to Lord Brouncker, the then President of the Royal Society. His letter, challenging the prevailing ideas about animal generation, was supported indeed by the authority of William Harvey.[br /]
[br /]
He wrote in 1699 to the society that, "human ingenuity will penetrate so deeply into that great secret that, by chance or by the dissection of the animalcule in the semen, we will come to see the entire man."[br /]
[br /]
This description seems to be little bit poetic, yet Leeuwenhoek had no doubt that the ‘entire man’, in whatever form, was there. The discovery of the spermatozoa was the crowning achievement of Leeuwenhoek’s microscopy. In due course of coming years, he described spermatozoa from fish, amphibians, birds, arthropods, mollusks and mammals.[br /]
[br /]
His work in this area led him to postulate a new definition of fertilization that ‘it occurred when the spermatozoa penetrated the egg’.[br /]
[br /]
He further studied the life cycle of ant. He was the first to show that, what had been generally accepted to be, ants’ eggs were really their pupae. He showed that it contained the perfect insect ready for emergence and the true eggs were much smaller and gave origin to larvae. He also proved that the sea mussel, and other shellfish were not generated out of sand or mud, but from spawn, by the regular course of generation. He also examined the embryos of freshwater mussel and observed then as to how they were consumed by animalcules. According to his description, many of them must have included ciliates in conjugation, flagellates, and the Verticella.[br /]
[br /]
[b]Other Important Discoveries[/b][br /]
[br /]
William Harvey, English physician, found blood circulation process in human body. In 1628, he described the motion of the heart and concluded that the blood left through the arteries and returned to the heart through the veins after it had passed through the flesh. But he had not proved that it moved in a closed system. By the middle of 17th century, British scientist Robert Hooke and Italian scientist Marcello Malpighi were engrossed in the study of anatomy. At that time Leeuwenhoek extended Malphighi’s 1660 demonstration of the blood capillaries, giving the first accurate description of red blood cells [RBCs] in 1684.[br /]
[br /]
Leeuwenhoek was eager to know how animals and plants transport nutrients. He studied the blood of fish, birds, tadpoles and mammals, including human beings. He showed, for the first time, the blood circulation of the tail capillaries of eels.[br /]
[br /]
[b]Summary[/b][br /]
[br /]
Leeuwenhoek’s voyage of experiments began with grinding tiny lenses to make simple microscopes and it continued till his death. He made his first observations of RBCs, protozoa, bacteria, and spermatozoa.[br /]
[br /]
Leeuwenhoek never wrote a single scientific paper. All his discoveries were written in old-fashioned Dutch. These letters were translated and published in English, a language of which Leeuwenhoek knew not a single word. The charm of the diction of his letters and the delightful style of the description are unique in the history of science.[br /]
[br /]
He should not be considered merely as an observational microscopist, for his work as an experimenter, allied to his skills as a section cutter and a dissector of minute organisms. His unequalled abilities give him additional status as a pioneer of 18th century experimental biology.[br /]
[br /]
[br /]
[br /]
- Antonie Van Leeuwenhoek[br /]
[br /]
[June 12, 1716][br /]
[br /]
One of the most imperfectly understood figures in the origins of experimental biology, Leeuwenhoek’s working manner that was essentially crude and undisciplined. He used those methods, which were untried before. His methods of investigation were lacking in refinement and objectivity. When he entered into the world of observational microscopy, he was unknowingly following the path of some well-known predecessors from different fields.[br /]
[br /]
Leeuwenhoek entered the field of science as a dwarf, where many giants were reigning over various branches. The new application of magnifying glasses and compound microscopes to biological studies in the mid-seventieth century was the most important factor in the subsequent development of the anatomical research. Primitive early microscopes enabled Robert Hooke to first observe the small compartments in the plants called cells and in the field of Histology, Malpighi to describe capillary circulation in the lungs, in 1661. Apart from it, with Swammerdam, he had revealed newer truths in the field of Anatomy in 1669. Insect morphology was described very well by Power in 1664 and by Robert Hooke in 1665. In Botany, a new branch of Plant Histology was developed by Grew in 1672 and by Malpighi in 1675.[br /]
[br /]
These scientists confined themselves largely to microscopic investigation with some small degree of preparative technique, i.e. the dissection of material. Leeuwenhoek entered the field with purely observational microscopy. It is noteworthy that he did not start his microscopic observations seriously until he was 40. His active period could be considered from 1673 to 1723.[br /]
[br /]
Documentary evidence of Leeuwenhoek’s works is found in the form of letters in which he recorded his observations. The bulk of his letters are preserved at the Royal Society’s rooms in Carlton House Terrace in London. The manuscript of his first letter sent in 1673 is lost, which appeared in Philosophical Transactions.[br /]
[br /]
[b]Making Of Microscopes[/b][br /]
[br /]
Building microscopes started as a hobby for Leeuwenhoek. He developed a way to grind tiny, high quality and high-power lenses. But his method of making the lenses was kept secret, so that there was no tradition left behind after him.[br /]
[br /]
A recent study has revealed that some of the lenses might have been made by grinding, while the best ones were blown. When a glass bulb is blown, a small drop of thickened glass forms at the bottom of the bulb. It is much like a drop sits at the bottom of the blown up soap bubble. Leeuwenhoek learned the method and by breaking away the excess glass carefully, he could get these crystallized small drops to be used as a lens. Then he devised a counter that allowed him to count the number of ‘minute creatures’ in a very small quantity of specimen, and then calculate numbers in the larger volume.[br /]
[br /]
He made microscopes using these lenses, with a purpose to view certain objects. In total he had around 500 lenses with the magnifying power between 50 and 300 times.[br /]
[br /]
His microscopes were simple instruments with a single small lens clamped between two metal plates. The object was placed on a fine pin and its distance from the plates adjusted by turning a screw. The entire instrument was 3 to 4 inches long. It had to be held up close to the eye, requiring good lighting and great patience when at use.[br /]
[br /]
A number of microscopes were auctioned and dispersed in 1747. Some 26 microscopes, complete with objects, were presented to the Royal Society. Two years after Leeuwenhoek’s death, most of his microscopes disappeared. Of these, only nine priceless microscopes, mounted in silver, are kept in the museum’s safe and their replica is on display for the public.[br /]
[br /]
[b]Discovery of Microorganisms[/b][br /]
[br /]
In 1673, Leeuwenhoek began writing a series of letters to the Royal Society of London, describing his microscopic observations. The first ever recorded letter contained some observations including mouth parts of fleas and stings of bees. It was translated into English and Latin and published in the Philosophical Transactions of the Royal Society.[br /]
[br /]
Leeuwenhoek, inspired by the appreciation, began to find out new organisms and their parts. In September of 1674, he observed the first microorganisms ever seen by a man, in the drop of puddle water !Beginning in 1676, he wrote around 30 letters to the Royal Society in London, describing the microorganisms termed by him as animalcules. They are now classified as protozoa, bacteria and rotifers.[br /]
[br /]
He classified the microorganisms found in what he called Little Animals in Rain Water. It was the first bacteria ever observed by man. His description read :[br /]
[br /]
"There was a fourth sort, which were so small that I was not able to give them any figure at all. These were a thousand times smaller than the eye of a large louse. These exceeded all the former in celerity. I have often observed them to stand still as it were on a point and then turn themselves about with that swiftness, as we see a top turn round, the circumference they made being no larger than that of a grain of small sand, and then extending themselves straight forward, and by and by lying in a bending posture. I discovered also several other sorts of animals; these were generally made up of such soft parts, as the former, that they burst asunder as soon as they came to want water."[br /]
[br /]
In his observations on rotifers in 1702, he remarked :[br /]
[br /]
"In all falling rain, carried from gutters into water-butts, animalcules are to be found; and that in all kinds of water, standing in the open air, animalcules can turn up. For these animalcules can be carried over by the wind, along with the bits of dust floating in the air."[br /]
[br /]
In a letter dated December 25, 1702, Leeuwenhoek gave descriptions of protists. It was large group comprising mostly single cell organisms such as protozoa, simple algae and fungi, slime moulds and the bacteria. There was a description of ciliates, which is a large group of advanced protozoans, including the ciliate Vorticella :[br /]
[br /]
"In structure these little animals were fashioned like a bell, and at the round opening they made such a stir, that the particles in the water thereabout were set in motion thereby…. And though I must have seen quite 20 of these little animals on their long tails alongside one other very gently moving, with outstretched bodies and straightened our tails; yet in an instant, as it were, they pulled their bodies and their tails together, and no sooner had they contracted their bodies and tails, than they began to stick their tails out again very leisurely, and stayed thus some time continuing their gentle motion : which sight I found mightily diverting."[br /]
[br /]
The first observations on living bacteria ever recorded, is found in the letter dated September 17, 1683. In this, he wrote to the Royal Society about his observations on the plaque between his own teeth. He repeated these observations on two ladies, probably his own wife and daughter. His description read :[br /]
[br /]
"I then most always saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving. The biggest sort… had a very strong and swift motion, and shot through the water (or spittle) like a pike does through the water. The second sort… oft-times spun round like a top…and these were far more in number."[br /]
[br /]
He also studied teeth of two old men who had never cleaned their teeth. In the mouth of one of those old men, Leeuwenhoek observed:[br /]
[br /]
"…an unbelievably great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time. The biggest sort… bent their body into curves in going forwards…. Moreover, the other animalcules were in such enormous numbers, that all the water… seemed to be alive."[br /]
[br /]
[b]Discovery of Spermatozoa[/b][br /]
[br /]
In the 17th and 18th centuries, no scientific problem was more laden with religious and philosophical overtones than the problem of generation. The problem was regarding how a mechanistic nature, devoid of spirit, could generate the purposeful complexity of living organisms, including human beings. Leeuwenhoek did not believed in the ‘theory of spontaneous generation’, prevailing in those days. Such theories asserted that the flea was produced from sand, others from dust and other such things. But Leeuwenhoek proved that it bred in the regular way to winged insects.[br /]
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John Ham, a student from the medical school at Leiden, brought him ‘the spontaneously discharged semen of a man who had lain with an unclean woman and was suffering from gonorrhea’, in which Ham himself had found ‘small animals with tails’. Leeuwenhoek also studied it and observed such ‘little animals’ within, which he called animalcula in semine masculino (animalcules in human semen). They had tails and could be alive for a few hours only. Now, he resumed observations of his own semen acquired, ‘not by sinfully defiling himself but as a natural consequence of conjugal coitus’. He observed a multitude of ‘animalcules’, less than a millionth the size of a coarse grain of sand and with thin, undulating transparent tails, which we know today as spermatozoa.[br /]
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He continued examining the semen specimen of birds, frogs, insects, cattle and several other species. He described these observations in a brief letter to Lord Brouncker, the then President of the Royal Society. His letter, challenging the prevailing ideas about animal generation, was supported indeed by the authority of William Harvey.[br /]
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He wrote in 1699 to the society that, "human ingenuity will penetrate so deeply into that great secret that, by chance or by the dissection of the animalcule in the semen, we will come to see the entire man."[br /]
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This description seems to be little bit poetic, yet Leeuwenhoek had no doubt that the ‘entire man’, in whatever form, was there. The discovery of the spermatozoa was the crowning achievement of Leeuwenhoek’s microscopy. In due course of coming years, he described spermatozoa from fish, amphibians, birds, arthropods, mollusks and mammals.[br /]
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His work in this area led him to postulate a new definition of fertilization that ‘it occurred when the spermatozoa penetrated the egg’.[br /]
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He further studied the life cycle of ant. He was the first to show that, what had been generally accepted to be, ants’ eggs were really their pupae. He showed that it contained the perfect insect ready for emergence and the true eggs were much smaller and gave origin to larvae. He also proved that the sea mussel, and other shellfish were not generated out of sand or mud, but from spawn, by the regular course of generation. He also examined the embryos of freshwater mussel and observed then as to how they were consumed by animalcules. According to his description, many of them must have included ciliates in conjugation, flagellates, and the Verticella.[br /]
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[b]Other Important Discoveries[/b][br /]
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William Harvey, English physician, found blood circulation process in human body. In 1628, he described the motion of the heart and concluded that the blood left through the arteries and returned to the heart through the veins after it had passed through the flesh. But he had not proved that it moved in a closed system. By the middle of 17th century, British scientist Robert Hooke and Italian scientist Marcello Malpighi were engrossed in the study of anatomy. At that time Leeuwenhoek extended Malphighi’s 1660 demonstration of the blood capillaries, giving the first accurate description of red blood cells [RBCs] in 1684.[br /]
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Leeuwenhoek was eager to know how animals and plants transport nutrients. He studied the blood of fish, birds, tadpoles and mammals, including human beings. He showed, for the first time, the blood circulation of the tail capillaries of eels.[br /]
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[b]Summary[/b][br /]
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Leeuwenhoek’s voyage of experiments began with grinding tiny lenses to make simple microscopes and it continued till his death. He made his first observations of RBCs, protozoa, bacteria, and spermatozoa.[br /]
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Leeuwenhoek never wrote a single scientific paper. All his discoveries were written in old-fashioned Dutch. These letters were translated and published in English, a language of which Leeuwenhoek knew not a single word. The charm of the diction of his letters and the delightful style of the description are unique in the history of science.[br /]
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He should not be considered merely as an observational microscopist, for his work as an experimenter, allied to his skills as a section cutter and a dissector of minute organisms. His unequalled abilities give him additional status as a pioneer of 18th century experimental biology.[br /]
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"I have oft-times been besought, by diverse gentlemen, to set down on paper what I have beheld through my newly invented Microscopia : but I have generally declined : first, because I have no style, or pen, wherewith to express my thoughts properly; secondly, because I have not been brought up to languages or arts, but only to business; and in the third place, because I do not gladly suffer contradiction or censure from others."[br /]
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[b]A LAYMAN OR A LEGEND ?[/b][br /]
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A man, who had hardly received any formal education, was able to build an edifice like medical field. Amazing, isn’t it ? Leeuwenhoek is the best example of how curiosity and passion lead us to reveal the mysteries of nature. He made simple microscopes from scratch due to lack of requisite material and the technical backup. If we compare the complex microscopes that we have today, we would probably say that Leeuwenhoek’s microscopes were like a vintage trove treasure from those days, in biological science that was then crawling at snail pace in the 17th century.[br /]
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The ‘germ’ of cell theory was sown in the 17th century. Robert Hooke was the first to use the term ‘cell’ in his Micrographia published in 1665. Living cells, or rather their walls were first described by Hooke, Malpighi, Grew and Leeuwenhoek. Leeuwenhoek was attracted towards microbiology after reading Hooke’s writings. Thus, Leeuwenhoek was not the first person to observe the ‘cell’ but he was first to see bacteria, spermatozoa and red blood cells. People sometimes called him ‘the inventor of microscopes’, which is not true, because the compound microscope (microscopes using more than one lens) had been invented around 40 years prior to Leeuwenhoek’s birth. Leeuwenhoek is called ‘the father of microbiology’, which is aptly termed. It is another thing that Leeuwenhoek could not draw well, so he hired an illustrator to prepare drawings of the things he observed through the microscope, and his descriptions of microorganisms with their illustrations are instantly recognizable.[br /]
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Leeuwenhoek, the person who discovered and described microorganisms for the first time, is considered today as the father of bacteriology and protozoology too. All of his theories and works were accepted because he could prove his work appropriately and in an illustrated manner in respect to other scientists. His nine microscopes and his invaluable letters, the best proof of his hard efforts, are on display in London. Many scientists are following his path, continuing the researches that he had conducted.[br /]
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His microscopes have benefited the world, paving the way for manufacture of medicines to cure diseases. His ‘magic’ instrument revealed the things never known before, like bacteria, protozoa, spermatozoa, capillary systems, the life cycle of insects, the red blood cells, and the corpuscles. The generations after him have become more intelligent and more health conscious gaining knowledge of such things. His discoveries helped other scientists see what caused in people, sickness. Without his researches, we would have to suffer through the pain and agony as we would not have had any kind of medicine to cure the diseased person. All past or present biological researches have roots in his hard put efforts. As the technology advanced, we have a cure for many dreaded diseases like cancer. We can now reveal the ‘mystery about the destroyed giants on the earth’ – dinosaurs.[br /]
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The genius of Leeuwenhoek is, probably, the best thing that happened to mankind. His discoveries helped us make the world a better place to live in. We can see the pathogens, which are invisible to naked eyes, with the vision invaluable gifted to us by Leeuwenhoek and can fight against them. With future technology, we will be able to hopefully sort out and solve many other health problems, as well as environmental problems like pollution. The latest researches in DNA replication and unveiling of the genetic code are all thanks to that brilliant vision, first striking the eyes of genius Leeuwenhoek. So how can we forget this great son who contributed so much that later generations may prosper and survive the ravages of time and diseases.[br /]
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Leeuwenhoek did not write any research paper, but instead he noted his microscopic observations. But these observations themselves were like research papers.[br /]
[br /]
This layman worked without any advanced scientific instruments and made a series of discoveries. His love for microscope transcended his liking for any other thing in life. Today, with the advancement of science, the method of making microscopes is so advanced that the objects can be magnified up to 1,00,000 times, using electron waves.[br /]
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The nature will keep unfolding itself with efforts. Leeuwenhoek had something ‘unique’ in his researches that should be inculcated – his faith in his ideas, passion for revealing the hidden truth, strong will-power, boundless patience and last but the most worthy – deep insight.[br /]
[br /]
[br /]
[br /]
A man, who had hardly received any formal education, was able to build an edifice like medical field. Amazing, isn’t it ? Leeuwenhoek is the best example of how curiosity and passion lead us to reveal the mysteries of nature. He made simple microscopes from scratch due to lack of requisite material and the technical backup. If we compare the complex microscopes that we have today, we would probably say that Leeuwenhoek’s microscopes were like a vintage trove treasure from those days, in biological science that was then crawling at snail pace in the 17th century.[br /]
[br /]
The ‘germ’ of cell theory was sown in the 17th century. Robert Hooke was the first to use the term ‘cell’ in his Micrographia published in 1665. Living cells, or rather their walls were first described by Hooke, Malpighi, Grew and Leeuwenhoek. Leeuwenhoek was attracted towards microbiology after reading Hooke’s writings. Thus, Leeuwenhoek was not the first person to observe the ‘cell’ but he was first to see bacteria, spermatozoa and red blood cells. People sometimes called him ‘the inventor of microscopes’, which is not true, because the compound microscope (microscopes using more than one lens) had been invented around 40 years prior to Leeuwenhoek’s birth. Leeuwenhoek is called ‘the father of microbiology’, which is aptly termed. It is another thing that Leeuwenhoek could not draw well, so he hired an illustrator to prepare drawings of the things he observed through the microscope, and his descriptions of microorganisms with their illustrations are instantly recognizable.[br /]
[br /]
Leeuwenhoek, the person who discovered and described microorganisms for the first time, is considered today as the father of bacteriology and protozoology too. All of his theories and works were accepted because he could prove his work appropriately and in an illustrated manner in respect to other scientists. His nine microscopes and his invaluable letters, the best proof of his hard efforts, are on display in London. Many scientists are following his path, continuing the researches that he had conducted.[br /]
[br /]
His microscopes have benefited the world, paving the way for manufacture of medicines to cure diseases. His ‘magic’ instrument revealed the things never known before, like bacteria, protozoa, spermatozoa, capillary systems, the life cycle of insects, the red blood cells, and the corpuscles. The generations after him have become more intelligent and more health conscious gaining knowledge of such things. His discoveries helped other scientists see what caused in people, sickness. Without his researches, we would have to suffer through the pain and agony as we would not have had any kind of medicine to cure the diseased person. All past or present biological researches have roots in his hard put efforts. As the technology advanced, we have a cure for many dreaded diseases like cancer. We can now reveal the ‘mystery about the destroyed giants on the earth’ – dinosaurs.[br /]
[br /]
The genius of Leeuwenhoek is, probably, the best thing that happened to mankind. His discoveries helped us make the world a better place to live in. We can see the pathogens, which are invisible to naked eyes, with the vision invaluable gifted to us by Leeuwenhoek and can fight against them. With future technology, we will be able to hopefully sort out and solve many other health problems, as well as environmental problems like pollution. The latest researches in DNA replication and unveiling of the genetic code are all thanks to that brilliant vision, first striking the eyes of genius Leeuwenhoek. So how can we forget this great son who contributed so much that later generations may prosper and survive the ravages of time and diseases.[br /]
[br /]
Leeuwenhoek did not write any research paper, but instead he noted his microscopic observations. But these observations themselves were like research papers.[br /]
[br /]
This layman worked without any advanced scientific instruments and made a series of discoveries. His love for microscope transcended his liking for any other thing in life. Today, with the advancement of science, the method of making microscopes is so advanced that the objects can be magnified up to 1,00,000 times, using electron waves.[br /]
[br /]
The nature will keep unfolding itself with efforts. Leeuwenhoek had something ‘unique’ in his researches that should be inculcated – his faith in his ideas, passion for revealing the hidden truth, strong will-power, boundless patience and last but the most worthy – deep insight.[br /]
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