824 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
(6) Miscellaneous. 
Some Practical Business Applications of the Microscope.*— The 
man who has learned the use of the Microscope has certainly gained a 
great deal ; but the man who claims to be a scientist without knowing 
the practical value of the Microscope, and without having learnt its use, 
ought not to be classed as such. The Microscope when first invented 
was considered as an accessory or a plaything. But since 1820, and 
later (1840), the first European oculists and scientists began to make 
microscopical researches, not only in the medical profession, but also in 
botanical, geological, and other studies. Since 1860 and 1870, the 
world over, the Microscope has been applied to almost every study and 
analysis. Had Galen, Celsus, and Hippocrates, and other ancients, had 
the use of the Microscope they would not have advocated the theory that 
the arteries in the human being contained air during life, instead of 
oxygenized blood. They were of the erroneous opinion that the blood 
simply acted as a humour in lubricating the tissues. Had it not been 
for the Microscope, James Paget, the great English surgeon and 
physician of St. Bartholomew’s Hospital, in the year 1834, would not 
have discovered the Trichina spiralis, which had already slaughtered its 
thousands, dating as far back as the time of Moses. 
The Microscope is certainly the greatest aid a scientific and a pro- 
fessional man can have. A physician without a Microscope is like a 
man without his hands : he is uncertain and unprotected. He cannot 
arrive at a correct and positive conclusion in diagnosing and prognosing 
his cases. It is important to have the Microscope at hand for examining 
the sputa of human beings, so as to be able to state positively whether 
or not the man is suffering with consumption (tuberculosis). It is 
important to be able to determine with certainty, at an early date, 
whether or not a man is suffering with cancer of the stomach by 
examining the vomits. A Microscope magnifying from 1 to 5000 
diameters is a most simple piece of apparatus. Every person can learn 
its use in a few hours. Every person should learn to use a Microscope, 
not only the professional man and scientist, but every business man, even 
the grocer, butcher, farmer, and the housewife. 
Everything that concerns a medical examination in a legal sense, or 
a legal examination in a medical sense, can be determined accurately by 
the use of the Microscope. For example, in the Cronin case of Chicago, 
where the medical experts demonstrated to a certainty that the blood, 
hair, and brain matter found in the Carlson cottage and sewer trap was 
that of a human body. Not only that, but they determined accurately 
and positively that the hair and blood found in the cottage and in the 
fatal trunk were that of Dr. Cronin, only in a modified condition ; all 
with the aid of the Microscope. 
Within the last decades scientists have demonstrated to a certainty 
the possibility of determining dried and old human blood-spots from 
that of animal blood, whether on clothing, wood, iron, or otherwise. 
Pathologists and histologists have also demonstrated the great value 
of the Microscope in determining positively the skin, hair, blood, brain- 
matter, also the excretions and secretions of the human being from that 
of the lower animals. 
* By Dr. F. Gaertner, Pittsburg, Pa., in Amer. Mon. Micr. Journ. See Engl. 
Mech., li. (1890) p. 483. 
