The Protection of Health 599 



teen quarts' capacity is to be placed in the room upon bricks 

 or other non-combustible material. Into this is put twelve 

 ounces of permanganate of potash, in crystals, and upon it is 

 poured about one quart of formalin. The one doing this should 

 leave the room immediately and seal the door with paper strips. 

 The temperature in the room should be kept above 70 Fahren- 

 heit, and the room remain closed from eight to ten hours. A 

 thorough airing and cleaning should follow. 



II. MODERN THEORIES OF IMMUNITY 



In current explanations of immunity or resistance to disease, 

 the general assumption is that microbes may be checked in their 

 multiplication and development, and their toxins neutralized 

 by the natural energies of the body. The natural energies that 

 are chiefly concerned in the subjection of the microbes, or the 

 neutralization of their toxins, are supposed to be of two kinds, 

 chemical and biological. 



293. Ehrlich's chemical theory. The chemical energies 

 concerned in immunity have been explained by the famous 

 German bio-chemist, Ehrlich, in what is often called the chemical 

 side-chain theory. According to this theory, the cells of the 

 organism are composed of chemical substances, which have 

 also side-chains or associates especially adapted to unite with 

 other chemical substances. The side chains are normally 

 concerned in absorbing and transmitting to the cells the food 

 products taken into the blood in the process of nutrition. But 

 in abnormal conditions, as when the organism is invaded by 

 disease bacteria, the chemical side chains or associates exhibit 

 a peculiar capacity of absorbing and neutralizing poisonous 

 or toxic substances produced by the bacteria. The cells, 

 moreover, directly they are affected through their side chains 

 by the bacterial toxin, are incited to extraordinary activity, 

 producing more of the side-chain substances which eventually 

 split off from the cells and circulate independently in the system. 

 The split off side chains or chemical substances form the antitoxin. 



