16 Microbes and You 



most modern instrument they could devise. It was a memorable 

 day for science on November 15, 1677, when this microscope was 

 presented to the Society and all could see for themselves that the 

 poor Dutch lens grinder from Delft was not fabricating;; his find- 

 ings. This instrument did not, however, measure up to the ones 

 that Leeuwenhoek had perfected. An invitation for Leeuwenhoek 

 to become a Fellow of the Society was soon on its way, and he 

 accepted the high honor and promised to serve faithfully during 

 the rest of his life. He never went back on his word. But he 

 never sent them a single microscope. In fact, he possessed one 

 instrument that no one was allowed to even look at— not even 

 members of his immediate family. 



In the tail of a small fish he saw capillary blood vessels through 

 which the blood passes from the arteries to the veins. This com- 

 pleted Harvey's discovery of the theory of blood circulation. As 

 Antony watched the blood cells passing through capillaries, prac- 

 tically in single file, a bright idea occurred to him which eventually 

 resulted in probably one of the earliest cures for a hangover. He 

 wrote that after a night of drinking he awoke in the morning 

 feeling sluggish, because his blood thickened, he postulated. 

 Several cups of black coffee in the morning, taken as hot as 

 possible until sweat broke out on his face, made him feel better. 

 If this treatment did not cure his sluggishness by opening up the 

 capillaries or by the thinning of his blood, he felt sure that no 

 prescription by an apothecary could cure the condition either. 

 He chanced to examine some of his teeth scrapings after such a 

 hot coffee episode, and he found that the small organisms scraped 

 from his front teeth no longer exhibited their frisky movements. 

 His back teeth, however, where the coffee had not come in contact 

 at such a high temperature, still showed active organisms when 

 scrapings were examined under his lenses. Selective heating in 

 flasks revealed the truth of his suspicions that the organisms could 

 be killed by heat. 



Of all the microbiologists none was so accurate, none so com- 

 pletely honest, and none had such common sense as Leeuwenhoek, 



