160 THE AMERICAN MONTHLY [May, 



the Progress of Microscopy in 1894. He first called attention to 

 the fact that during the past year considerable activity had been 

 shown in the " br;iss and glass " world. Several new models of 

 microscopes and new forms of apparatus having been produced, 

 he adverted to Herr E. Leitz's microscope with a '' bent claw" 

 foot, which appeared about the end of 1893, and which was at 

 present a nearer approach to the English model than any other 

 Continental microscope that had hitherto been made. The 

 President then referred to the three and four-legged stands of 

 Messrs. Swift, to the new mechanical stage, and to the improved 

 form of Cambridge Rocking microtome of the same makers, 

 Messrs. Ross and Co's " Eclipse" microscopes were criticised, 

 and Mr. Nelson commented favorably on the ring- foot adopted 

 by these makers for this class of student's microscope. Messrs. 

 Watson's new model " Van Heurck " stand was noticed, as was 

 also Messrs. Baker's photographic microscope, and their in- 

 stantaneous photographic shutter, which had been adapted for 

 photo-micrography. The President called attention to the 

 progress that had been made in light screens for photo-micro- 

 graphy and critical illumination, referring especially to the 

 work done in this direction by J. W. Loviboiid and J. W. 

 Gifford, which he considered would lead to most important 

 results. After reviewing a pamphlet by Allan Dick, describing 

 how his petrological microscope could be used lor general 

 microscopic work, the remaining portion of the address was 

 given up to a mosr, lucid review of Lewis Wright's theory of 

 microscopic vision, which appeared in the English mechanic 

 during the past year, and which Mr. Nelson considered to be 

 a most valuable contribution to the study of microscopic 

 optics. — English Mechanic. 



MICROSCOPICAL NOTES. 



Vaselin in Microscopy. — Gawalowski proposes to replace 

 cedar oil and other liquids used for oil immersion for objectives 

 by vaselin, whose refractive index is 1.40. — Rundschau. 



Fine Mounts of Caterpillars.— Mr. ('. P. Bates, 853 Main 

 street, Petaluma, Sonoma County, California, prepares fine 

 mounts of Caterpillars. We advise those who are interested in 

 the subject to correspond with him. 



