ANAPHYLAXIS 23 



The principles of artificial immunity, as remarked before, have 

 only recently become understood, but the science of immunology 

 is yearly becoming extended. As this paper is being written, 

 experiments with preventive and curative inoculations against 

 typhus fever and against infantile paralysis are being worked 

 out and there is reason to hope that before another year dawns 

 these two terrible diseases may be added to the already consid- 

 erable list of diseases which can be prevented by artificially 

 produced immunity. Smallpox, rabies, cholera and diphtheria 

 are some of the more important diseases whose guns have been 

 unloaded by this means. While, as remarked before, compara- 

 tively little advance has been made in the application of the 

 principles of immunity to animal parasites, yet there seems to be 

 hope that in the coming years many diseases caused by Protozoa 

 and worms may be conquered by further knowledge of immu- 

 nology. 



Anaphylaxis. — Mention should be made of the phenomenon 

 of anaphylaxis, commonl}^ defined as an exaggerated suscepti- 

 bility to the poisonous effect of foreign substances in the blood, 

 and to account for which many different explanations have been 

 proposed. Based on extensive experimental work, Novy and 

 De Kruif have recent!}' (1917) offered a new and revolutionary 

 explanation which is bound to be of far-reaching significance. 

 According to these workers, normal circulating blood must be 

 presumed to contain a substance, termed the " poison matrix," 

 comparable in a general way with the substance in the blood 

 known as fibrinogen. The latter substance, under certain condi- 

 tions or in the presence of certain reagents, is transformed into 

 fibrin, which forms a network of fibers in the meshes of which the 

 blood corpuscles are caught, and by means of which the clotting of 

 blood is effected. The same reaction which leads to the coagu- 

 lation of blood also transforms the poison matrix into an actively 

 poisonous substance or " anaphylatoxin," which produces the 

 symptoms commonly known as anaphylaxis. Furthermore, it 

 is shown that the transformation of the poison matrix into 

 anaphylatoxin is induced or accelerated by the addition of al- 

 most any foreign substance to the blood, e.g., bacteria, trypano- 

 somes, tissue cells, agar, peptone, starch, various salts, and even 

 distilled water. In other words " the circulating blood, through 

 a variety of agents, may be changed from a beneficial and harm- 



