T6 



THE AMERICAN MONTHLY 



[April, 



had any appreciable interest in the 

 microscope whatever, certainly more 

 than five per cent, of its members 

 would take a journal like this. 



As a matter of fact, physicians in 

 general are utterly incapable of using 

 the microscope in their practice. 

 They cannot tell uric acid from triple 

 phosphates, tube-casts from cotton- 

 fibres, cancerous from normal cells, 

 or a starch-grain from a blood-cor- 

 puscle. Does this seem incredible? 

 What shall be said of the physician 

 who bought a fine immersion-lens and 

 returned it as worthless, because he 

 "immersed" it by filling the back with 

 water and screwing it on the stand ! 

 Or of the other one who tried to ex- 

 amine a lump of coal with a ^^-inch! 



A good story is told of the physic- 

 ian who showed what he vowed was 

 a cancer-cell to a visitor, but the visi- 

 tor failing to see the structure, re- 

 quired it to be particularly designated, 

 when he found the supposed cancer- 

 cell was a distorted air-bubble. An- 

 other physician found some tube- 

 casts, which were mere scratches upon 

 a slip of glass purposely made to test 

 his knowledge. Another who had used 

 a microscope for several years, had 

 never heard of opaque illumination, 

 and he examined everything, large or 

 small, with a ^ objective and a B ocu- 

 lar. 



One of our prominent manufactur- 

 ers of objectives once remarked that 

 physicians judge of a microscope by 

 its power, and therefore his mistake 

 had been in making objectives of \- 

 inch focus instead of ^-inch. The 

 meaning of this is simply that the 

 higher power is the more saleable. 



A little more knowledge of the mi- 

 croscope would prevent physicians 

 from following too blindly, the teach- 

 ings of incompetent and unscientific 

 observers. We would hear less non- 

 sense about new organisms found in 

 the blood, and there would not be so 

 many absurd observations published 

 about disease-germs, extravagant as- 

 sertions about the structure of proto- 

 plasm and about the diagnosis of the 



general constitution of a patient by 

 the examination of the white blood- 

 corpuscles. Perhaps the editors of 

 many of our medical journals would 

 do well to read up a little on the mi- 

 croscope — just enough to keep up the 

 credit of their papers. 



o 



Microscopic Angular Aperture, 

 — We desire to call particular atten- 

 tion to the article by the Hon. J. D. 

 Cox, published this month, for we are 

 sure that any one who reads it care- 

 fully will find it both interesting and 

 instructive. Mr. Cox has explained 

 several points in regard to the focus 

 and the field of n^croscope objec- 

 tives that doubtless have been very 

 puzzling to some readers, with great 

 clearness. We commend the article 

 to every one who uses the microscope, 

 whether interested in the subject of 

 aperture or not, for it is a subject 

 that should be more or less under- 

 stood by every microscopist. 



The article by Prof. Van Dyck will 

 possess considerable interest, in that 

 it clearly explains a phenomenon 

 which must be familiar to every one 

 who uses a microscope. 



We reserve for next month an arti- 

 cle by Mr. E. Gundlach, in which he 

 endeavors to prove that immersion- 

 condensers cannot be made, accord- 

 ing to the present system, of suffici- 

 ently wide angular aperture to meet 

 the requirements of the future, and 

 describing a new form of condenser 

 of larger aperture. Also another arti- 

 cle, which was prepared for this num- 

 ber, defining the term "numerical 

 aperture," and showing its relation to 

 angular aperture. 



o 



Swarm-spores of Closterium. — 

 Mr. William Trelease has called our 

 attention to the probability that the 

 phenomena described in the last num- 

 ber of the Journal as the reproduc- 

 tion of Closterium by swarm-spores, is 

 not a process of propagation, but that 

 the moving spores, and the projections 

 through the cell, belong to a parasitic 

 plant, Chytridium. 



