Beschreibung:

LEEUWENHOEK, Antoni van (1632-1723). Ondervingen en beschouwingen der onsigtbare geschapene waarheden, vervat in verscheydene Brieven, geschreven aan de... Koninklijke Societeit in Engeland . Leiden: Daniel van Gaesbeeck, 1684. 4 o (200 x 156 mm). 10 engraved text illustrations. Modern vellum; folding cloth case. FIRST EDITION of letters 32 and 33, and the first separately published edition of any of Leeuwenhoek's letters. "Antoni van Leeuwenhoek, who lacked formal university training in the sciences, philosophy, or languages, surely ranks among the greatest autodidacts in the history of science and medicine. Born into a comfortable middle-class Dutch family, he passed his long life almost entirely in Delft. There he had two careers: the first as a civil servant, the second as a microscopist of international renown... Although a man of limited theoretical skills, he was a consummately acute observer, and for fifty years he patiently and painstakingly documented the hidden realms of nature in a way no one had done before him" (Grolier Medicine ). A skilled lens grinder, Leeuwenhoek produced a total of about 550 lenses during his lifetime, perfecting the microscope sufficiently to enable him to make unprecedented observations of sub-visible life. Although his ignorance of foreign languages forced him to rely on Dutch authors and Dutch translations of standard scientific works, he was aided and encouraged in his work by friends such as Constantin Huygens and Reinier de Graaf One beneficial consequence of his relative isolation from the main currents of contemporary scientific scholarship was that "he was thus able to work with full independence and to make a sharp distinction between the empiricism and speculation that marked the sometimes chaotic world of seventeenth-century science. Leeuwenhoek apparently regarded speculation as an academic occupation... He usually set out his observations fully, as facts, and only then in a separate section, allowed himself to wonder what those facts might mean". While his hundreds of observations included inorganic as well as organic structures, Leeuwenhoek's major contributions were in the field of microbiology: "Early in his career as a scientist, he observed what he described as animalcules or 'little animals' [ dierkens ] in water, and from then on he described in considerable detail a spectrum of microorganisms never before detected, including bacteria, protozoa, and rotifers" (Grolier Medicine ). He devised for his observations a system of micrometry, utilizing as standards a grain of coarse sand, a hair from his beard, and two micro-organisms. One of Leeuwenhoek's lifelong concerns and the area of his work that most caught the attention of his contemporaries, was the study of sexual reproduction. His work includes the first full descriptions of spermatozoa, which he considered to be "little men," the origin of all new animal life, regarding the egg as primarily a source of nutrients (in opposition to Harvey, who took the contrary view). He also investigated the development of other mammals as well that of birds, fish, reptiles and mollusks, and the cumulative effect of his work was to provide evidence aginst the then prevalent theory of spontaneous generation. He independently discovered and correctly identified blood corpuscles, and, attempting to draw an analogy between animal and plant systems, minutely analyzed the systems of nutrient transport in plants.Although he developed no general theory, Leeuwenhoek's work raised crucial questions and helped establish the microsope as an indispensable tool for medical and biological research. Leeuwenhoek's scientific communications consisted exclusively of letters to fellow scientists, the majority addressed to the Royal Society in London. 165 were published, in two chronological sequences, numbered 28-146 and I-XLIV (letters 1-27 were not published separately, although abstracts appeared in the Philosophical transactions ). 120 letters