36 THE MICROSCOPE. March 
War with the Microbes. 
By Dr. E. A. de SCHWEINITZ, 
WASHINGTON, D. C. 
[Report of an address before the Chemical Society of Washington, D. C., 
March 9, 1897,] 
After a brief history of the discoveries which lead up 
to the germ theory of disease, the speaker said that Pas- 
teur had done much to throw light upon the origin of 
these poisons. As the ferment alters the grape juice, so 
does a microscopic form of life bring about the changes in 
dead animal and vegetable matter, and also those condi- 
tions in the living body which we call disease. 
Many of these microscopic forms of single-celled plants: 
the bacteria, naturally live on dead organic matter, bat 
they also flourish in the living body, unlimited in variety, 
appearance and behavior. It is possible also to culti- 
vate them upon specially prepared solutions. 
The diphtheria germs find their most comfortable 
habitat upon certain mucous membranes, others in the 
lungs, some in the digestive tract, still others in the 
blood, while others again confine themselves to certain 
external cells and membranes. In artificial culture nearly 
all thrive upon beef broth. Some prefer the beef broth 
with an excess of acid, others with an excess of alkali. 
Some demand the addition of sugar or glycerine, others 
the addition of both sugar and. acid, while some are sat- 
isfied with a diet of phosphates, salt and water, 
In 1882, Dr. Salmon demonstrated that these poison. 
germs could be used to fortify both man and animals 
against the attacks of these bacteria. This could be ac- 
complished by introducing into the circulation of the 
animala small quantity of the poison of the germ, so that 
when the germ itself was injected the poison which it 
produced was without effect. This chemical vaccination 
was tried for diphtheria, tetanus, anthrax, cholera, typ- 
