Antonie van Leeuwenhoek

---

Birth & Death: Delft, Netherlands October 24, 1632 - August 30, 1723

---

Antonie van Leeuwenhoek was an indefatigable scientist, inventor and tradesman from Delft, Netherlands who lived at the turn of the 16th and 17th centuries. He is commonly known as "the Father of Microbiology"; that title is well deserved, but diminishes his importance in other disciplines. His original thoughts and dedicated actions advanced so many fields that he is considered to be one of the great scientists of all time..

By refining the glass buttons that were then used by drapers to magnify their view of cloth, Leeuwenhoek created the first true (single lens) microscopes and was the first person to observe and describe single-celled organisms (microorganisms) that he termed "animcules". He was also the first to record microscopic observations of muscle fibers, bacteria, spermatozoa and blood flow in capillaries (small blood vessels), and to advance techniques in the micro-dissection of tissues. This work helped lay the foundations of Medicine, Surgery, and Cell Biology, besides Microbiology.

Van Leeuwenhoek's early discoveries in the field of microbiology can be likened to Galileo's early discoveries in the field of astronomy. Both men used the newly available optical technologies of their day to make major discoveries that entirely overturned traditional beliefs and theories in their respective fields, and both men were initially met with strong skepticism and resistance to the inevitable conclusions that their discoveries led to. Ultimately van Leeuwenhoek was more fortunate than Galileo in that his discoveries were widely accepted and applauded in his lifetime, whereas Galileo's were not appreciated until long after his death.

Van Leeuwenhoek was an indefatigable workman, who ground over 500 optical lenses. Nine of the more than 400 different microscopes he built still exist today . These microscopes are made of silver or copper metal frames holding his hand-ground lenses. Those nine that have survived the years are able to magnify up to 270 times, but on the basis of his drawings, van Leeuwenhoek is thought to have made some instruments that could magnify up to 500 times.

He was a remarkably creative abstract thinker who was interested in knowledge for its own sake. His curiosity was legendary, as was his openness to new ideas. Some of that latter quality might have been helped by his lack of any formal science training in his youth. He was never indoctrinated into the strict dogma of his day. Although he considered his technical improvements in optics to be quite proprietary, and closely guarded his inventions from others, he freely shared the findings that he made from them. In doing so, he "opened up the entire world of microscopic life to the scientific community".

Overview life and work

Antonie Leeuwenhoek was christened as Thonis - yet signed his name Antonij, which corresponds with the name 'Antony' in modern English. The first name of 'Antonie', by which he has become known, was invented by American scholars and never used in his lifetime. Van Lueeuwenhoek's given name can also be found written as Anthon, Anthony, Antonie, Antony, Anthonie, Antoni, Antonio and Anthoni. Leeuwenhoek, believing that he was by then an established figure, himself added a 'van' to his name in 1686. His correct name thereafter is therefore Antony van Leeuwenhoek; his full name being Thonius Philips van Leeuwenhoek (pronounced 'Laywenhook').

Born the son of a basket maker, at age 16 he secured an apprenticeship with a Scottish cloth merchant in Amsterdam.

There, in 1648, van Leeuwenhoek saw his first simple microscope (a microscope with a single lens), a tool used by textile merchants. This particular instrument was a magnifying glass mounted on a small stand and enlarge by 3 times the cloth viewed through it (magnifying power of 3). He soon acquired one for his own use in business. After doing well in the cloth trade, he moved back to Delft to start his own drapery business, which was a great financial success. In 1660, he was appointed chamberlain of the Lord Regents of Delft, a mark of distinction.

He likely read the book by Robert Hooke, titled Micrographia soon after it was published in 1665. That book is believed to have influenced van Leeuwenhoek to use his microscopes for the purpose of investigating the world beyond the fabrics that he sold.

In 1669 he obtained a degree in geography, and was appointed geographer in 1679.

Leeuwenhoek made good use of the huge lead provided by his method. He studied a broad range of microscopic phenomena, and shared the resulting observations freely with groups such as the English Royal Society. Such work firmly established his place in history as one of the first and one of the most important explorers of the microscopic world. With regards to the construction of his microscopes, however, Leeuwenhoek maintained throughout his life that there were aspects of their construction "which I only keep for myself," including in particular his most critical secret of how he created lenses.

Recognition by the English Royal Society

After developing his method for creating powerful lenses and applying them to a thorough study of the microscopic world, Leeuwenhoek was introduced via correspondence to the English Royal Society by the famous Dutch Physician Regnier de Graaf. He soon began to send copies of his recorded microscopic observations to the Royal Society. In 1673 his earliest observations were published by the Royal Society in its journal: Philosophical Transactions. Amongst these published observations were Van Leeuwenhoek's accounts of bee mouthparts and stings... .

Despite the initial success of Van Leeuwenhoek's relationship with the Royal Society, this relationship was soon severely strained. In 1676 his credibility was questioned when he sent the Royal Society a copy of his first observations of microscopic single celled organisms. Heretofore, the existence of single celled organisms was entirely unknown. Thus, even with his established reputation with the Royal Society as a reliable observer, his observations of microscopic life were initially met with certain skepticism. Eventually, in the face of Van Leeuwenhoek's insistence, the Royal Society arranged to send an English vicar, as well as a team of respected jurists and doctors to Delft, Holland to determine whether it was in fact Van Leeuwenhoek's ability to observe and reason clearly, or perhaps the Royal Society's theories of life itself that might require reform. Finally, Van Leeuwenhoek's observations were fully vindicated by the Society. He was awarded an invitation to th membership, and became Fellow of the Royal Society, 1680.

Van Leeuwenhoek's vindication resulted in his appointment as a Fellow of the Royal Society in that year. After his appointment to the Society, he wrote approximately 560 letters to the Society and other scientific institutions over a period of 50 years. These letters dealt with the subjects he had investigated.

In 1981 The British microscopist Brian J. Ford found that Leeuwnehoek's original specimens had survived in the collections of the Royal Society of London. They were found to be of high quality, and were all well preserved. Ford carried out observations with a range of microscopes, adding to our knowledge of Leeuwenhoek's work.

Later discoveries

Amongst Van Leeuwenhoek's many discoveries are: in 1674 he discovered infusoria (dated zoölogical category,) in 1676 he discovered bacteria, in 1677 he discovered spermatozoa and in 1682 he discovered the banded pattern of muscular fibers.

He died at the age of 90, on August 30, 1723 at Delft.

Revolutionizing the microscope and microscopy

Leeuwenhoek's interest in microscopes and a familiarity with glass processing led to one of the most significant, and simultaneously well-hidden, technical insights in the history of science. By placing the middle of a small rod of lime glass in a hot flame, Leeuwenhoek could pull the hot section apart like taffy to create two long whiskers of glass. By then reinserting the end of one whisker into the flame, he could create a very small, high-quality glass sphere. These spheres became the lenses of his microscopes, with the smallest spheres providing the highest magnifications. An experienced businessman, Leeuwenhoek realized that if his simple method for creating the critically important lens was revealed, the scientific community of his time would likely disregard or even forget his role in microscopy. He therefore allowed others to believe that he was laboriously spending most of his nights and free time grinding increasingly tiny lenses to use in microscopes, even though this belief conflicted both with his construction of hundreds of microscopes and his habit of building a new microscope whenever he chanced upon an interesting specimen that he wanted to preserve.

Religious interpretations of van Leeuwenhoek's discoveries

Van Leeuwenhoek was a Dutch Reformed Calvinist. He often referred with reverence to the wonders God designed in making creatures great and small. He believed that his amazing discoveries were merely further proof of the great wonder of God's creation.

Van Leeuwenhoek's discoveries did overturn the traditional belief of the time in the spontaneous generation of life. This belief or theory was generally held by the 17th century scientific community, and was also tacitly endorsed by the 17th century Church. Still, the Church's position on the exact nature of spontaneous generation was ambivalent. Possibly because van Leeuwenhoek's discoveries of microscopic life appeared at the time to pose no direct challenge to any Church doctrines such as the doctrine of creationism, the Church made no effort to challenge or question any of van Leeuwenhoek's discoveries in any way. It was only 200 years later when Charles Darwin incorporated van Leeuwenhoek's discoveries of microscopic life as a key element of his theory of evolution that it was first recognized that van Leeuwenhoek's findings might lend support to any challenge to traditional Church doctrine on the origins of life.

Association with Vermeer

Van Leeuwenhoek was a contemporary of that other famous Delft citizen, painter Johannes Vermeer, who was baptized just four days earlier. It has been suggested that he is the man portrayed in two of Vermeer's paintings of the late 1660s, The astronomer and The geographer. Because they were both relatively important men in a city with only 24,000 inhabitants, it is possible that they were at least acquaintances. Also, it is known that Van Leeuwenhoek acted as the executor when the painter died in 1675. However, others argue that there appears to be little physical similarity.

External links

• Dutch online biography of van Leeuwenhoek
• Paper on Leeuwenhoek's original specimens
• Vermeer connection website
• University of California, Berkeley article on van Leeuwenhoek
• Works by Antoni van Leeuwenhoek at Project Gutenberg
• Retrospective paper on the Leeuwenhoek research by Brian J. Ford.