Leeuwenhoek and his discoveries. What made the Dutch biologist Anthony van Leeuwenhoek famous? In this section, we will introduce you closer to this great man.

25.01.2021

Antoni van Leeuwenhoek
Anthony van Leeuwenhoek ( -) Date of Birth: Date of death: The country:

Netherlands

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Anthony van Leeuwenhoek(Antoni van Leeuwenhoek, Thonius Philips van Leeuwenhoek; October 24, Delft - August 26, Delft) - Dutch naturalist, microscope designer, founder of scientific microscopy, member of the Royal Society of London (since 1680), who studied the structure of various forms of living matter with his microscopes. In the Russian historical tradition, there are different spellings of the scientist's name - Anton, Anthony and Antonius.

Biography

Anthony van Leeuwenhoek was born on October 24, 1632 in Delft, the son of Philips Thoniszoon, a basket maker. Anthony took the surname Leeuwenhoek from the name of the Lion Gate adjacent to his house (Dutch. Leeuwenpoort). The combination "guk" ( hoek) in his pseudonym means "corner".

Father died when Anthony was six years old. Mother Margaret van den Berch (Grietje van den Berch) sent the boy to study at a gymnasium in the suburbs of Leiden. The future naturalist's uncle taught him the basics of mathematics and physics. In 1648, Anthony went to Amsterdam to study as an accountant, but instead of studying, he got a job in a haberdashery shop. There he first saw the simplest microscope - a magnifying glass that was mounted on a small tripod and used by textile workers. Soon he bought himself the same.

Creating a microscope

Leeuwenhoek read the work of the English naturalist Robert Hooke "Micrography" (Eng. Micrographia), published in , shortly after its publication. Reading this book aroused his interest in studying the natural environment with the help of lenses. Together with Marcello Malpighi, Leeuwenhoek introduced the use of microscopes for zoological research.

Having mastered the craft of a grinder, Leeuwenhoek became a very skilled and successful lens maker. Installing his lenses in metal frames, he built a microscope and with its help carried out the most advanced research at that time. The lenses that he made were uncomfortable and small, and a certain skill was needed to work with them, but with their help a number of important discoveries were made. In total, during his life he made more than 500 lenses and at least 25 microscopes, 9 of which have survived to this day. It is believed that Leeuwenhoek was able to create a microscope that allowed for a 500x magnification, but the maximum magnification that can be obtained using surviving microscopes is 275.

Lens manufacturing method

For a long time it was believed that Leeuwenhoek made his lenses by filigree grinding, which, given their tiny size, was an unusually laborious task that required great precision. After Leeuwenhoek, no one has been able to produce devices similar in design to the same image quality.

However, in the late 1970s, a method of making lenses was tested not by grinding, but by melting a thin glass thread. This method made it possible to manufacture lenses that fully meet all the necessary criteria, and even completely recreate the microscope of the Leeuwenhoek system, although an examination of his original microscopes of the 17th century in order to confirm or refute this hypothesis was never carried out. The lenses were made by melting the end of a glass filament to form a glass ball, followed by grinding and polishing one of its sides (plano-convex lens). The resulting glass ball works great as a converging lens. Thus, there are two versions of the manufacture of lenses by Leeuwenhoek - using the thermal grinding method (glass ball) or by additional grinding and polishing one of its sides in the usual way after heat treatment.

Discoveries

Leeuwenhoek sketched the observed objects, and described his observations in letters (about 300 in total), which he sent to the Royal Society of London for more than 50 years, as well as to some scientists. In 1673, his letter was first published in the Philosophical Papers of the Royal Society of London. Philosophical Transactions).

However, in 1676 the validity of his research was called into question when he sent out a copy of his observations of unicellular organisms, the existence of which had not been known until that time. Despite his reputation as a trustworthy researcher, his observations were met with some skepticism. To check their authenticity, a group of scientists headed by Nehemiah Gru went to Delft, who confirmed the authenticity of all studies. February 8, 1680 Leeuwenhoek was elected a full member of the Royal Society of London.

Among other things, Leeuwenhoek was the first to discover

Anthony van Leeuwenhoek (1632-1723).

On one of the warm May days in 1698, a yacht stopped on a large canal near the city of Delft, in Holland. A very elderly but unusually vigorous man boarded her. From the excited expression on his face, one could guess what brought him here is not an ordinary thing. On the yacht, the guest was met by a man of enormous stature, surrounded by a retinue. In broken Dutch, the giant greeted the guest who bowed in respect. It was the Russian Tsar Peter I. His guest was a resident of Delft - the Dutchman Anthony van Leeuwenhoek.

Anthony van Leeuwenhoek was born on October 24, 1623 in the Dutch city of Delft to Philips Antonisson and Margaret Bel van den Burch. His childhood was not easy. He received no education. The father, a poor craftsman, gave the boy an apprenticeship to a cloth maker. Soon Anthony began to independently trade in manufactory.

Then Leeuwenhoek was a cashier and accountant in one of the trading establishments in Amsterdam. Later, he served as a guardian of the judicial chamber in his native city, which, according to modern concepts, corresponds to the positions of a janitor, stoker and watchman at the same time. Leeuwenhoek became famous because of his unusual hobby.

Even in his youth, Anthony learned how to make magnifying glasses, became interested in this business and achieved amazing art in it. In his spare time, he enjoyed grinding optical glasses and did so with virtuoso skill. In those days, the strongest lenses magnified the image only twenty times. Leeuwenhoek's "microscope" is essentially a very powerful magnifying glass. She magnified up to 250-300 times. Such powerful magnifying glasses were completely unknown at the time. Lenses, i.e. Leeuwenhoek's magnifying glasses, were very small - the size of a large pea. They were difficult to use. A tiny glass in a frame with a long handle had to be applied close to the eye. But, despite this, Leeuwenhoek's observations were distinguished for that time by great accuracy. These wonderful lenses turned out to be a window to a new world.

Leeuwenhoek was engaged in improving his microscopes all his life: he changed lenses, invented some devices, varied the conditions of the experiment. After his death, 273 microscopes and 172 lenses were counted in his office, which he called a museum, 160 microscopes were mounted in silver frames, 3 in gold. And how many devices he lost - after all, he tried, at the risk of his own eyes, to observe under a microscope the moment of the explosion of gunpowder.

At the beginning of 1673, Dr. Graaff sent a letter to the secretary of the Royal Society of London. In this letter, he reported "about a certain inventor living in Holland by the name of Anthony van Leeuwenhoek, who makes microscopes far superior to those of Eustachius Divina known so far."

Science should be grateful to Dr. Graaf for the fact that, having learned about Leeuwenhoek, he managed to write his letter: in August of the same year, Graaf died at the age of thirty-two. Perhaps, if not for him, the world would never have known about Leeuwenhoek, whose talent, deprived of support, would have withered away, and his discoveries would have been made again by others, but much later. The Royal Society contacted Leeuwenhoek and a correspondence began.

Carrying out his research without any plan, the self-taught scientist made many important discoveries. For almost fifty years, Leeuwenhoek carefully sent long letters to England. In them, he talked about such truly extraordinary things that gray-haired scientists in powdered wigs shook their heads in amazement. In London, his reports were carefully studied. For fifty years of work, the researcher discovered more than two hundred species of the smallest organisms.

Leeuwenhoek really made such great discoveries in biology that each of them could glorify and forever keep his name in the annals of science.

At that time, biological science was at a very low stage of development. The basic laws governing the development and life of plants and animals were not yet known. Scientists also knew little about the structure of the body of animals and humans. And many amazing secrets of nature were revealed before the eyes of every observant naturalist who possessed talent and perseverance.

Leeuwenhoek was one of the most prominent researchers of nature. He was the first to notice how blood moves in the smallest blood vessels - capillaries. Leeuwenhoek saw that blood is not some kind of homogeneous liquid, as his contemporaries thought, but a living stream in which a great many tiny bodies move. Now they are called red blood cells. There are about 4-5 million red blood cells in one cubic millimeter of blood. They play an important role in the life of the body as oxygen carriers to all tissues and organs. Many years after Leeuwenhoek, scientists learned that it is thanks to red blood cells, which contain a special dye hemoglobin, that blood has a red color.

Another discovery of Leeuwenhoek is also very important: he first saw spermatozoa in the seminal fluid - those small cells with tails that, penetrating into the egg, fertilize it, as a result of which a new organism arises.

Examining thin plates of meat under his magnifying glass, Leeuwenhoek discovered that meat, or rather, muscles, consists of microscopic fibers. At the same time, the muscles of the limbs and trunk (skeletal muscles) consist of striated fibers, which is why they are called striated, in contrast to the smooth muscles that are found in most internal organs (intestines, etc.) and in the walls of blood vessels.

But Leeuwenhoek's most surprising and most important discovery is not this. He was the first who had the great honor to lift the veil into the hitherto unknown world of living beings - microorganisms that play a huge role in nature and in human life.

Some of the most perspicacious minds have previously expressed vague conjectures about the existence of some smallest creatures, invisible to the naked eye, responsible for the spread and occurrence of infectious diseases. But all these conjectures remained only guesses. After all, no one has ever seen such small organisms.

In 1673 Leeuwenhoek was the first person to see microbes. For long, long hours, he examined everything that caught his eye through a microscope: a piece of meat, a drop of rainwater or hay infusion, the tail of a tadpole, the eye of a fly, a grayish coating from his teeth, etc. What was his amazement when in the dentist on the fly, in a drop of water and many other liquids, he saw a myriad of living beings. They looked like sticks, and spirals, and balls. Sometimes these creatures had bizarre processes or cilia. Many of them moved quickly.

Here is what Leeuwenhoek wrote to the English Royal Society about his observations: “After all the attempts to find out what forces in the root (horseradish. - Approx. Aut.) act on the tongue and cause its irritation, I put about half an ounce of the root in water: in in a softened state it is easier to study.A piece of root remained in the water for about three weeks.April 24, 1673, I looked at this water under a microscope and with great surprise saw in it a huge number of tiny living creatures.Some of them were three or four times in length more than wide, although they were not thicker than the hairs covering the body of the louse ... Others had the correct oval shape. There was also the third type of organisms, the most numerous, - the smallest creatures with tails.

Thus, one of the great discoveries was made, which marked the beginning of microbiology - the science of microscopic organisms.

Leeuwenhoek was one of the first to conduct experiments on himself. It was from his finger that blood flowed for research, and he placed pieces of his skin under a microscope, examining its structure in various parts of the body and counting the number of vessels that penetrate it. Studying the reproduction of such little respected insects as lice, he put them in his stocking for several days, endured bites, but in the end he found out what kind of offspring his wards had.

He studied the secretions of his body depending on the quality of the food eaten.

Leeuwenhoek also experienced the effects of drugs. When he fell ill, he noted all the features of the course of his illness, and before his death, he meticulously recorded the extinction of life in his body. During the long years of association with the Royal Society, Leeuwenhoek received from him many necessary books, and over time his horizons became much wider, but he continued to work not in order to surprise the world, but in order to "saturate, as far as possible, his passion to penetrate into the beginning of things ".

“In my observations, I spent more time than some people think,” Leeuwenhoek wrote. “However, I was engaged in them with pleasure and did not care about the chatter of those who make such a fuss about it: “Why spend so much work, what is the use of it?”, But I do not write for such, but only for lovers of knowledge.

It is not known for sure whether anyone interfered with Leeuwenhoek's activities, but he once accidentally wrote: "All my efforts are aimed at one goal only - to make the truth obvious and apply the little talent I have received to divert people from old and superstitious prejudices."

In 1680, the scientific world officially recognized Leeuwenhoek's achievements and elected him a full and equal member of the Royal Society of London - despite the fact that he did not know Latin and, according to the then rules, could not be considered a real scientist. Later he was admitted to the French Academy of Sciences. Many famous people, including Peter I, came to Delft to look into the wonderful lenses. The published secrets of the nature of Leeuwenhoek revealed the wonders of the microworld to Jonathan Swift. The great English satirist visited Delft, and we owe two of the four parts of the amazing Gulliver's Travels to this trip.

Leeuwenhoek's letters to the Royal Society, to scientists, to political and public figures of his time - Leibniz, Robert Hooke, Christian Huygens - were published in Latin during his lifetime and took up four volumes. The last one came out in 1722, when Leeuwenhoek was 90 years old, a year before his death.

Leeuwenhoek went down in history as one of the greatest experimenters of his time. Glorifying the experiment, he wrote the prophetic words six years before his death: "One should refrain from reasoning when experience speaks."

From the time of Leeuwenhoek to the present day, microbiology has made great progress. It has grown into a widely branched field of knowledge and is of great importance for all human practice - medicine, agriculture, industry - and for the knowledge of the laws of nature. Tens of thousands of researchers in all countries of the world tirelessly study the vast and diverse world of microscopic creatures. And they all honor Leeuwenhoek, an outstanding Dutch biologist, from whom the history of microbiology begins.

October 24, 1632 - August 26, 1723

Dutch naturalist, microscope designer, founder of scientific microscopy, member of the Royal Society of London

Biography

Anthony van Leeuwenhoek was born on October 24, 1632 in Delft, the son of Philips Thoniszoon, a basket maker. Anthony took the surname Leeuwenhoek from the name of the Lion Gate (Dutch. Leeuwenpoort) adjacent to his house. The combination "guk" in his pseudonym means "corner" (hoek).

Father died when Anthony was six years old. Mother Margaret van den Berch (Grietje van den Berch) sent the boy to study at a gymnasium in the suburbs of Leiden. The uncle of the future naturalist taught him the basics of mathematics and physics. In 1648, Anthony went to Amsterdam to study as an accountant, but instead of studying, he got a job in a haberdashery shop. There he first saw the simplest microscope - a magnifying glass that was mounted on a small tripod and used by textile workers. Soon he bought himself the same.

In 1654 he returned to his native Delft, where he then lived until his death. Having bought a shop, he engaged in trade. According to a number of testimonies, Leeuwenhoek was friends with the artist Vermeer, and after his death he became his executor.

Creating a microscope

Leeuwenhoek read the work of the English naturalist Robert Hooke "Micrographia" (eng. Micrographia), published in 1665, shortly after its publication. Reading this book aroused his interest in studying the natural environment with the help of lenses. Together with Marcello Malpighi, Leeuwenhoek introduced the use of microscopes for zoological research.

Having mastered the craft of a grinder, Leeuwenhoek became a very skilled and successful lens maker. In total, during his life, he made about 250 lenses, achieving a 300-fold increase. Installing his lenses in metal frames, he built a microscope and with its help carried out the most advanced research at that time. The lenses that he made were uncomfortable and small, and a certain skill was needed to work with them, but with their help a number of important discoveries were made.

Lens manufacturing method

However, in the late 1970s, at the Novosibirsk Medical Institute, the method of manufacturing lenses was tested not by grinding, but by melting a thin glass thread. This method made it possible to manufacture lenses that fully meet all the necessary criteria and even completely recreate the microscope of the Leeuwenhoek system, although an examination of his original microscopes of the 17th century in order to confirm or refute this hypothesis was never carried out. The lenses were made by melting the end of a glass filament to form a glass ball, followed by grinding and polishing one of its sides (plano-convex lens). The resulting glass ball works great as a converging lens. Thus, there are two versions of the manufacture of lenses by Leeuwenhoek - using the thermal grinding method (glass ball) or by additional grinding and polishing one of its sides in the usual way after heat treatment.

Discoveries

Observed objects Leeuwenhoek sketched, and described his observations in letters (about 300 in total), which he sent to the Royal Society of London for more than 50 years, as well as to some scientists. In 1673, his letter was first published in Philosophical Transactions, a journal of the Royal Society of London.

However, in 1676, the reliability of his research was called into question when he sent a copy of his observations of single-celled organisms, the existence of which had not been known until that time. Despite his reputation as a trustworthy researcher, his observations were met with some skepticism. To check their authenticity, a group of scientists headed by Nehemiah Grew went to Delft, who confirmed the authenticity of all studies. February 8, 1680 Leeuwenhoek was elected a full member of the Royal Society of London.

Among other things, Leeuwenhoek was the first to discover erythrocytes, described bacteria (1683), yeast, protozoa, lens fibers, scales (shrunken cells) of the epidermis of the skin, sketched spermatozoa (1677), the structure of insect eyes and muscle fibers. He found and described a number of rotifers, hydra budding, etc. He discovered ciliates and described many of their forms.

Leeuwenhoek's works

Sendbrieven ontleedingen en ontkellingen etc., (1685-1718) (need)
Opera omnia s. arcana naturae, (1722) (lat.)

Through Leeuwenhoek's magic device
On the surface of a drop of water
Discovered by our science
Surprising life traces.
But for the abysses where meteors fly
Neither big nor small
And equally endless spaces
For microbes, people and planets.
Nikolay Zabolotsky

(Antoni van Leeuwenhoek) Dutch naturalist, microscope designer, founder of scientific microscopy, member of the Royal Society of London, who studied the structure of various forms of living matter with his microscopes.

The biography of Anthony van Leeuwenhoek is amazing. Nothing foreshadowed scientific activity and great discoveries. Moreover, he did not receive a proper education, did not study at universities. His interest in microscopes would now be called just a hobby (hobby). But he certainly had the talent of a researcher and an irresistible desire to engage in these studies.

Anthony van Leeuwenhoek was born on October 24, 1632 in the city of Delft. His father Phillips Antonius van Leeuwenhoek was a master basket maker and his mother Margaretha (Bel van den Burch) came from a very wealthy and respected family of brewers. His father died very early, when Anthony was only five years old. Little is known about his childhood. He attended a school near Leiden, then lived with his uncle, who taught him the basics of mathematics and physics. At the age of 16, he began working as an apprentice trader in a flax shop in Amsterdam.

There, the young man first saw a simple microscope - a magnifying glass that was mounted on a small tripod and used by textile workers. Soon he bought himself the same.

Obviously, the quality of the lenses did not suit the young researcher. Leeuwenhoek began to manufacture lenses for his microscopes himself, and achieved the best results and kept the method of their production a secret.

Leeuwenhoek's microscope Leeuwenhoek's microscope was extremely simple and consisted of two metal plates. A lens was fixed in the center of one plate, a needle was attached to the other, the tip of which was moved in focus with the help of screws. The object was mounted on a needle or glued to it.

And through this "magic device" Leeuwenhoek saw an amazing microcosm, about which no one in those days had any idea. The researcher saw living creatures that moved, had flagella and cilia, they moved and multiplied. Microbes, bacteria, bacilli, yeast - it was all exciting and new.

Leeuwenhoek's research is unusually varied. He carefully prepared sections of the trunks of various trees, made excellent drawings and descriptions of the vessels and the arrangement of cells in the medullary rays. He first discovered crystals in plants, and by studying the structure of various seeds and their germination, he established the difference between monocots and dicots.

He was the first to see how blood circulates in the smallest blood vessels. He discovered that blood is not a homogeneous liquid, as his contemporaries thought, but a living stream in which a great many tiny particles move. Now they are called red blood cells.

For the first time, he saw spermatozoa in the seminal fluid - those small cells with tails that, penetrating into the egg, fertilize it, as a result of which a new organism arises and develops.

Leeuwenhoek was the first to discover the faceted structure of the insect eye, transverse muscle fibers, tubules of dental substance, lens fibers, scales, etc. He discovered and described a number of rotifers, hydra budding, and most importantly, discovered ciliates and described quite a few of their forms. He was the first resolute and strong opponent of the doctrine of the spontaneous generation of life, which dominated the biology of that period.

Leeuwenhoek's most outstanding discovery was the simplest organisms and bacteria found in the water. For fifty years of work, the researcher discovered more than two hundred species of the smallest organisms. These observations opened a new era in biology.

Drawings and descriptions of Leeuwenhoek

Anthony van Leeuwenhoek observed, sketched and described everything he saw with his microscopes. In 1673, his friend, the famous Dutch physician Reinier de Graaf, sent a letter to the Royal Society of London (the most authoritative scientific center of that time) from Leeuwenhoek with the first report of his invention and discovery. In the drawings attached to the scientist's reports, one can see various forms of bacteria: bacilli, cocci, spirilla, filamentous bacteria.

In 1673 Leeuwenhoek's letter was first published in Philosophical Papers, a journal of the Royal Society of London. In the future, for 50 years, he sent his messages there. The scientist's research was so innovative, and the microcosm he discovered so unusual, that despite his reputation as a trustworthy researcher, his observations were sometimes perceived with some skepticism. To check their authenticity, a group of scientists headed by Nehemiah Gru went to Delft, who confirmed the authenticity of all the studies. February 8, 1680 Leeuwenhoek was elected a full member of the Royal Society of London.

His letters were first published in scientific journals, and in 1695, they were published in Latin as a separate large book entitled "The Secrets of Nature, discovered by Antony Leeuwenhoek with the help of microscopes."

Leeuwenhoek corresponded with famous scientists - Leibniz, Robert Hooke, Christian Huygens. To look into the wonderful lenses, many famous people, scientists, politicians came to Delft, including Peter I, William III of Orange, Jonathan Swift.

Thanks to Leeuwenhoek's microscopes and his research, an unknown and unexplored microcosm has opened up to mankind, as huge and interesting as the comsos, stars and the Universe, which Galileo Galilei studied through a telescope.

Leeuwenhoek's microscope aroused great interest among contemporaries and did not die out over the centuries. It would seem, what can be surprised at the beginning of the 21st century, when there are electron microscopes? The fact is that Leeuwenhoek, in addition to his outstanding scientific discoveries and legendary microscopes, left several mysteries to his descendant.

Undoubtedly, even a very experienced researcher of our day could not, using this microscope, see everything that was described by Leeuwenhoek, since the scientist over the years has developed a perfect method of observation. He never published the method he used for "better research", saying that "I will keep it for myself." During his research, Leeuwenhoek designed various ingenious devices that made it easier for him to observe or carry out experiments.

Another important feature. In the second half of the 17th century, an outstanding scientist manually made microscopes with one rather strong lens, which made it possible to examine objects in detail. Leeuwenhoek's microscopes were essentially large lenses mounted on a tripod. But he kept the secret of making lenses a secret. The Utrecht Museum houses Leeuwenhoek's microscope, which gives a magnification of 300 times. And this is with one lens. Unfathomable!

Now the secret of making lenses has been unraveled. Leeuwenhoek put a small glass rod into the flame of the burner, then took it out in molten form and reinserted a piece of fiber into the burner, thus obtaining a very small glass ball. This ball was a high quality lens. This is one of the most revolutionary ideas in the history of science, which could only be unraveled in the 20th century. In 1957, S. Stong, using a glass thread, obtained several samples of such lenses. Independently of him, the Russian scientists A. Mosolova and A. Belkin achieved the same results in Novosibirsk.

Leeuwenhoek went down in history as one of the greatest experimenters of his time. Glorifying the experiment, he wrote prophetic words six years before his death: "One should refrain from reasoning when experience speaks."

Unfortunately, there is very little biographical information about Leeuwenhoek's life.

Anthony van Leeuwenhoek was born on October 24, 1632 in Delft, Holland. Father and mother were respected burghers and were engaged in basket weaving and, which was especially appreciated at that time, brewing. Leeuwenhoek was raised by his mother, as his father died early. She dreamed of making an official out of her son and therefore sent him to school. At the age of 15, Anthony decided to leave school and move to Amsterdam, where he began to study trading in a shop, where he worked as an accountant and cashier.

It is known that he acquired a manufacturing shop, where he worked for several years. In June 1654, he married Barbara de Mey (Barbara de Mey), four of their children died in infancy, daughter Maria was not just his only surviving child, she was his friend and enthusiastically examined everything that her father examined in a microscope. His first wife Barbara died in 1666 and in 1671 Leeuwenhoek married Cornelia Swalmius, with whom he had no children.

In his native city of Delft, he was a well-known and respected person; in the local town hall, he received the position of guardian of the court chamber, then inspector of the city's wine chamber. He lived a long life, doing his research, improving microscopes, lenses and research methods. Anthony van Leeuwenhoek died on August 26, 1723 in Delft and bequeathed his microscopes to the Royal Society of London.

During his long life, the great inventor and scientist Anthony van Leeuwenhoek made more than 500 optical lenses and about 25 microscopes. Only 9 have survived to this day and these are priceless relics of the history of science, the history of search and great discoveries.

Leeuwenhoek Anthony van (1632-1723), Dutch scientist, creator of the microscope, discoverer of the microworld, founder of microbiology.

Born October 24, 1632 in Delft in a family of brewers. After studying at school until the age of 15, he went to work in a shop (he served as an accountant and cashier, studied trading). At the age of 20, he opened his own manufactory and began to lead the life of a respectable family burgher. But this practical, businesslike man had a hobby that made him famous through the ages.

When Leeuwenhoek first made a magnifying glass is not exactly known. However, this happened at a young age. Holland was famous for its craftsmen, and magnifying glasses were not new there. New was the use that Leeuwenhoek found for his own hand-made device, which he called "microscope". However, in the current understanding, it rather resembled a very strong magnifying glass (100-300-fold increase), and a tiny one - the size of a pea. Inserted into a frame made by Leeuwenhoek, this magnifying glass required a certain skill in handling, but with its help the master discovered amazing things. Trying to find the reason for the spicy taste of pepper, Leeuwenhoek decided to examine a drop of pepper infusion under his microscope. And, to my own surprise, I saw that the two-week-old infusion was teeming with tiny organisms, which the observer called "animaculi". So Leeuwenhoek became the first person to see microbes.

In 1673, a friend of the inventor, the famous Dutch physician R. Graaf, sent a letter to the Royal Society of London (the most authoritative scientific center of that time) from Leeuwenhoek with the first report on his invention and discovery. This correspondence was maintained by Leeuwenhoek for the next 50 years. He also wrote to famous scientists: X. Huygens, R. Hooke, G. Leibniz, R. Boyle and others. His letters in Latin, the recognized language of science, contained reports of amazing discoveries: soil and even ... scraped from the teeth.

February 8, 1680 Leeuwenhoek was elected a full and equal member of the Royal Society of London. His letters were first published in scientific journals, and in 1695 they were published in Latin as a separate book entitled "The Secrets of Nature, discovered by Antony Leeuwenhoek with the help of microscopes." In the drawings attached to the scientist's reports, one can see various forms of bacteria: bacilli, cocci, spirilla, filamentous bacteria.