CHAPTER III 



THE 

 MICROSCOPE 



How some were held. 



An early microscope. 



How was the microscope invented? Was it much simpler at one 

 time or is it still in its original form ? What is the use of a microscope f 

 Is there a definite technique to be observed in using it? 



Biology has contacts with other sciences. Inventions and dis- 

 coveries by physicists and chemists have made possible the explana- 

 tions of many biological facts. It is almost impossible to discuss 

 biology without including some physics and chemistry. The in- 

 vention and improvement of the microscope by physicists have 

 been largely responsible for the rapid progress of biology. 



The history of the microscope. In Holland, in the seven- 

 teenth century, Anthony Von Leeuwenhoek (1632-1725) ex- 

 perimented with lenses, grinding hundreds and using them in 

 various combinations to get different magnifications. He im- 

 proved those that had formerly been used. He used dust, wood, 

 and crystals to try the strength of his lenses. As he was interested 

 in natural history, he investigated the minute structure of living 

 things. He had little education and his researches were not con- 

 ducted on an extremely scientific basis, and, therefore, his work was 

 somewhat unsystematic and disconnected. However, his im- 

 proved lenses opened up an entirely new field, namely, the inves- 

 tigation of minute living things. Scientists could now actually 

 confirm certain of their speculations. A short time before the 

 microscope was improved, William Harvey, an English physician, 



19 



