CHAPTER XI. 
MICROCHEMISTRY. 
1. The Application of Microchemical Analysis. —In 
few fields have the possibilities of the microscope been 
less fully realized than in pure and applied chemistry. 
A science which deals with the character and behavior 
of chemical substances should surely take into account 
the characteristic crystals of which, under certain con- 
ditions, many such substances are composed. Yet 
chemists trained to study gross color reactions and 
precipitates have too often regarded the microscope as 
a strange and impracticable instrument. Systems of 
recondite and elaborate secondary tests have been built 
up, while the direct study of fundamental physical char- 
acters has been neglected. Although the toxicologist and 
the medical microscopist have used microchemical tests 
with such good results that in those special fields they 
are of importance, in general the adoption of these 
methods by chemists is slow; and only the develop- 
ment of petrography, the microscopic study of rock 
sections, has at last, during very recent years, called 
general attention to their importance. 
The study of microchemistry is by no means limited 
to the examination of crystalline forms alone, as might 
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