MICEOPHOTOGKAPIIY WITH SIMPLE APPAHATUS. 
(By H. B. Pajjker, Assistant Surgeon, United States Marine-Hospitad Service.) 
The art or mechanics of photography has in the last few j^ears 
become very useful in pathological, histological, and bacteriolog- 
ical work. Almost every laboratory is supplied with an approved 
apparatus, while the independent workers convert their photo- 
graphic apparatus, either kodak or camera, into some form of 
apparatus to meet their particular desires or needs. As a reward 
for their efforts they meet with varying degrees of success, so 
much so that in modern medical literature it is impossible in many 
instances to determine from the results whether the writer had in 
his possession an approved model or a simple makeshift of his own. 
With low diameters almost any combination of microscope, 
camera, and illuminant will produce a fair picture in the hands of 
an amateur familiar with outdoor photographic processes. To 
obtain success with the higher diameters special apparatus is 
required, and these, I regret to say, are so expensive and difficult of 
manipulation that their use is prohibited in any but the more lux- 
uriously equipped laboratories. The average size of the picture 
desired in bacteriological work is 2 inches; for pathological* work 
somewhat larger; the average size of the plate in the modern 
microphotographic outfit is 6|- by 8^- inches to 8 by 10 inches with 
a bellows extension that will average 5 feet. This long extension 
was for a time an advantage, permitting the use of low-power 
objectives, amplification being secured by distance, but with the 
advent and perfection of apochromatic objectives, compensation 
and projection oculars, and instruments of greater precision in 
sectioning pathological and histological processes, the use of the 
long bellows is practically limited to achromatic and specially 
devised photographic objectives. A disadvantage ])robably more 
})romiiient than the preceding is the necessity of an arc light with 
its elaborate system of condensers and absorbing cells as the illum- 
inant, a system too complex for the small and moderate size 
laboratory. 
To overcome some of the disadvantages mentioned we have con- 
structed an apparatus on the usual principle of the horizontal 
instrument but have reduced the size of the bellows extension to 
32 inches and the size of the plate to 4 by 5 inches. We used an 
ordinary lantern-slide camera, which gave the results shown in 
the illustrations. 
