296 THE AMERICAN MONTHLY [Oct 



Smith, New Orleans ; "The Structure and Classification 

 of Diatoms, Dr. Chas. E. Bessey, Lincoln, Nebr. ; the 

 '•Structure of the Soft Palate," W. F. Mercer, Ithaca, 

 N. Y.; "Construction of a New Stand for Microscopical 

 Work," Dr. A. G-. Field, Des Moines, Iowa. 



Friday Afternoon. — A symposium on the use of the 

 microscope by teachers and individual workers was pre- 

 sented, Professor Gage, of Cornell, contributing a paper 

 on "Histology," Professor Bleile, of Columbus, one ou 

 "Physiology and Bacteriology," and Professor Bessey one 

 on "Botany." 



Friday Evening. — Mr. J. F. Stone of 694 East Broad 

 street, gave an informal reception to the society, when the 

 microscopists were entertained with views of the Grand 

 Canon of the Colorado. 



Saturday Morning. — The society elected officers and 

 adjourned. The new officers, are : President, Dr. A. M. 

 Bleile, Columbus ; first vice president. C. H. Eigemann, 

 Indiana university ; second vice president, Dr. M. A. 

 Veeder, of Lyons, N. Y.; secretary, H. B. Ward,Lincoln, 

 Nebr; treasurer, J. C. Smith, New Orleans ; custodian, 

 Magnus Pflaum, of Pittsburg. 



Achromatics versus Apochromatics. 



EDMUND. J. SPITTA. 



It has been said that "seeing what you know and know- 

 ing what you see" are two very different things. By this 

 is meant that it is far easier to recognize special charac- 

 teristic features in anything with which you are familiar, 

 than to discover new details about the object for which 

 you are neither mentally prepared nor have practised 

 your eye to see. This is especially true with the micro- 

 scope and applies very strongly in determining the rela- 

 tive value of lenses by different makers, but perhaps more 

 especially so when a definite decision has to be arrived at 



