ADVERTISEMENT. 



In the five plates of worms, some of the figures are rep- 

 resented as viewed with the microscope, and their increase 

 as to the diameter, the surface, and the whole hody, re* 

 lates to the glasses, that were used. Tlie proportion not- 

 ed helow has been settled "by 6lroe»e, in conformity to the 

 calculations of Hoffmann, a celebrated optician of Leipsic. 



By the tube A they are magnified ; 



In diameter. In superficies. In the entire body. 



No. 6. — 16 times . 25 times . . . 4,096 times. 



5 31 ... 961 29,791 



4. — 52 . . 2,734 .... 140,608 



3 78 . . 6.084 .... 487,552 



2 154 . 25,716 .... 3,632,254 



1. — 189 . . 35,721 .... 6,731,269 

 0. — 300 . . 90,000 . . . 27,000,000 



[This work has already appea»ed in the Italian, Ger- 

 man, and French languages. The following recommenda- 

 tion of it is from the Medical Professors of Harvard Uni- 

 versity. 



« This book appears to us highly valuable on account 

 of the numerous facts it contains, and as comprising the 

 information which is scattered throngli many volimiinous 

 works. The subject which it embraces is such as to enti- 

 tle it to the attention of every medical practitioner. It 

 seems to us to fill a space, whicli is not occupied by any 

 single work in the English language. 

 2 



