22 THE AMERICAN MONTHLY [Jan 



croscopy and bacteriology. With the constant advances 

 of sanitary science there will be increased demands for 

 the services of scientific physicians, in the country as 

 well as in the city. 



The physician is often called as an expert and if he is 

 able to use the microscope, in its application to forensic 

 medicine, his knowledge will be in demand and his evi- 

 dence of greater value. The microchemistry of poisons 

 is of itself a vast field of research. The detection of 

 crime is often made easy by means of the microscope in 

 honest and skilful hands. It may be of great value in 

 detecting erasures and changes in manuscript, the char- 

 acter of ink, lead penciling, tracings, and the detection of 

 forged signatures. The identification of blood stains, 

 seminal stains, hair fiber, etc., often leads to the discov- 

 ery of the guilty, and has given to the microscope its 

 reputation as an "unerring detective." 



The application of the microscope to agriculture, hor- 

 ticulture, viticulture, mineralogy, contagious diseases of 

 animals, food adulterations, the analysis of water and 

 milk, and the micro-chemical investigations of poisons, 

 etc, might be profitably dwelt upon did time permit. 



For the ambitious investigator or student there is a 

 vast field for investigation outside the limits of medical 

 microscopy. There is scarcely a microscopic object whose 

 every detail cannot with the camera's aid, be reproduced 

 on paper, hence the great value of photomicrographs for 

 illustrations or reproductions. Grlass negatives of micro- 

 scopic objects have been admitted as evidence in courts 

 of justice. From such negatives the lantern slide may be 

 made and the same object be projected upon canvass 

 screens by means of sunlight or electric light. This is a 

 valuable method of teaching classes and illustrating lec- 

 tures. Charcot illustrated pathological conditions in his 

 clinical lectures in this manner and it was looked upon as 

 a marvelous, novel, and attractive method of teaching. 



