readily seen by the naked eve, and those-'one-thinl as wide mar 

 be seen without the microscope. Lines too fine to be seen 

 singly with the microscope can be seen and resolved if ruled close 

 together in bands. 



Cutting Sections of Coal— The discussion in the English 

 journals as to the correctness of the assertion in the Micrographic 

 dictionary, that coal can be softened by soaking in a solution of 

 carbonate of potash, sufficiently to be sliced with a razor, has 

 ended with the concession that it is lignite, and not coal, that can 



this special and not usual sense, has caused many and perplexing 

 failures to experienced workers as well as to beginners. 



Microscopical Diagnosis.— Under this title, Professor Charles 

 H. Stowell, of the university of Michigan, has brought out an 

 octavo volume of 250 pages. The book, which is published bv 

 Geo. S. Davis, of Detroit, at fo.OO, is well printed and freely illus- 

 trated with wood cuts and lithographs. Its character is not well 

 indicated by its name. It consists of a collection of essays upon 



other, and no special connection with the technical subject an- 

 nounced in the title. Part i, of 03 P'^s, relates (with the excep- 

 tion of the chapter on stare'.!, which seems to belong to Part 11) to 



nosisf It ,\ • 



an introductory chapter on the' instrument, treats of blood, epi- 

 thelium, sputa, etc, muscle, urinarv deposits, parasite 



1 by eight lil 



:»pters of t 



mp,.ru 



similar studies of the more important medicinal plants, this collec- 

 tion will become a treatise of great importance and interest Part 

 in is the series of very instructive and popular papers on the pre- 

 paration and mounting of microscopic objects, originally published 



