1890.] MICROSCOPICAL JOURNAL. 257 



A Handy Photo-Microj^i-aphic Cjunera. 



By W. H. WALMSLEY, 



PHILADELPHIA, PA. 



[Read at the Detroit Meeting, 1890.] 



Although photography in conjunction with ordinary microscopical 

 observations (in other words, photo-micrography) has undoubtedly 

 grown in usefulness and popularity among workers with the micro- 

 scope during the past five years, there can be no doubt that its aid is 

 very sparingly employed — a fact greatly to be regretted. For it is 

 quite self-evident that the value of any microscopical research would 

 be greatly enhanced, not only to the observer himself, but to his read- 

 ers (in the event of his work being published) , by full and accurate 

 illustrations. Very few microscopists are competent draughtsmen, 

 or capable of making drawings of objects under the lens, at all 

 correctly, or even presentable as illustra'tions thereof. And a drawing 

 thus made is always permeated more or less by the imagination of the 

 artist; so that the greater his skill in that direction the more likely is 

 he to introduce features, not as rendered by the tube, but as he thinks 

 he sees them. To be sure, photographic reproductions of many micro- 

 scopic objects are in a majority of cases not by any means perfect, or 

 what one could desire, but they are vastly superior to almost any draw- 

 ings in their accurate delineation of the various features of the speci- 

 men. The saving of time is another most .important feature, as a 

 dozen negatives may be taken in less time than that required to make a 

 single careful drawing. 



In the old "Wet-plate" days, the comparative insensitiveness of 

 which precluded the use of a lamp as the illuminator, only those pos- 

 sessing a well filled pocket-book or having access to the resources of 

 a governmental or college laboratory could avail themselves of the aid 

 of photography in connection with the microscope. But the modern 

 gelatine "Dry-plate" has placed in the hands of every one a cheap 

 and efficient means of doing the highest class of work readily and per- 

 fectly. The very highest powers may be used with the light from an 

 ordinary petroleum lamp. I have a print from a negative of Ple7(}-o- 

 sig))ia aiig-iilatwn magnified 2,400 diameters, by Spencer's jL homo- 

 geneous objective; the illuminant being an ordinarv single wick, coal 

 oil lamp. It is the work of Dr. J. E. Baker, of Wvoming, Ohio, 

 and is fully equal to the best work of Zeiss' Apocliromatics, with 

 the highest sources of illumination and every appliance of modern skill 

 and ingenuity, regardless of cost, that have been given to the micro- 

 scopic world during the past six months. 



Why, then, has the use of photography not become more general 

 among microscopists.? Simply from the fancied difficulties of the 

 necessary but simple manipulations required ; and from the real one of 

 the absence of any form of camera which could find a regular and per- 

 manent home upon the work-table ; occupying no more space than the 

 microscope itself, and always ready for immediate use. The latter is 

 a most important requisite. How frequently does the student find in 

 the course of his observations upon living and other tissues, features 

 that are vital toward proving the truth of his researches, but so eva- 

 nescent that the lapse of even a few minutes may suffice to obliterate 



