1 882.] Microscopy. 763 



gradually rounded down, the outline becomes undefined toward 

 its juncture with the relieving surface, owing to the white of the 

 raised portion being partially transparent and permitting the dark 

 to show through it when it is thinned down. Care is taken to 

 finish this dark surface as much as possible with the cutting tools, 

 and so separate the white from it as to leave it smooth and un- 

 scratched. A final polish is given it, however, with putty powder 

 applied dry with a stiff brush, but the utmost care is necessary in 

 this operation, as the slightest slip will ruin the work. This is 

 the cameo cutter's work, the mountings being the jeweler's work. 

 The cameos sell, unmounted, for about $25." 



The Microscope in the Detection of Forgery.— The Bos- 

 ton Journal of Chemistry for August, publishes some " interesting 

 paragraphs " from a recent lecture in England, by Mr. Jno. 

 Rogers. The quotations are an abstract, though not so credited, of 

 remarks in Dr. R. H. Ward's lecture on the Practical Uses of the 

 Microscope, delivered as president's address at the Buffalo meet- 

 ing of the American Society of Microscopists, in August, 1879. 

 Not only is the substance taken from that source, but numerous 

 phrases and entire sentences are copied word for word. Dr. 

 Ward's publication upon the subject was based upon more than 

 twenty years of original work in a field then new and practically 

 unoccupied, and, in appropriating his work, credit should have 

 been given so fully and conspicuously, that it could not be over- 

 looked or misunderstood. 



Kent's Infusoria.— The sixth part of Mr. W. Saville Kent's 

 Manual of the Infusoria, just issued by David Bogue, of London, 

 completes a work that will be a classic in microscopy. The hook 

 is the more remarkable as showing how much of excellent work 

 can be accomplished in a limited time, the author having ex- 

 plained that when he undertook this study, ten years ago, he was 

 but a beginner in practical microscopy. Finding the literature of 

 his chosen subject to be fragmentary and scattered, and practically 

 unavailable, he undertook to compile a manual that should bring 

 to the knowledge of English-speaking microscopists the vast 

 number of species of Infusoria now known to science. It soon 

 became evident that the original plan of covering the broad field 

 occupied by Ehrenberg and Pritchard, was far too comprehensive 

 tor the present state of knowledge. A more limited group was 

 therefore adopted, represented by the flagellate, ciliate and ten- 

 tacuhferous Protozoa ; and these have been elaborated with great 

 thoroughness, much original research being incorporated along 

 with the record of previously described forms. Questions of 

 arnmty and derivation, of interest in general biology, have been 

 w ell kept in view; and an additional plate with description of the 

 apparatus specially adapted to the study of infusorial life, will be ap- 

 Precated even by experienced students. The work comprises three 



