13 



structure of the white matter of the brain. From his 

 own teeth he extracted a white substance which, mixed 

 with pure rain-water, showed some kind of small animal- 

 cules, the motions of which were " very pleasing to 

 behold." He examined the spermatozoa from whales 

 to spiders, and contested the theory of spontaneous 

 generation. 



The Royal Society of London, during a period of 

 fifty years, received from him three hundred and seventy- 

 five letters and papers. {From notes by Mr. Jones, of 

 the Liverpool Medical Institute) . 



His lenses had a focus of \ inch, and it is wonderful 

 how much he accomplished, and how minute the objects 

 he observed. 



The construction of the single microscope is so simple 

 that it is susceptible of but little improvement, and has 

 therefore undergone but few alterations. 



Quoting again from the French, with reference to the 

 compound microscope. The Neapolitan, Francois Fontana, 

 was the first in 1646 who described the instrument in 

 his " New Observations Terrestrial and Celestial." He 

 pretended also to have discovered it in 1618, one year 

 before Cornelius Drebell had brought it to England. 



Several authors say that it was about this time that 

 this instrument received from Demisiano the name of 

 microscope, and that the name telescope is equally due to 

 him. Professor Carpenter, however, ascribes the inven- 

 tion of the name to Giovanni Faber, 162 5. 



Amongst the first compound microscopes, one refers 

 to those of Hooke (1656), Eustachio Divini (1668), 



