218 WARFIELD T. LONGCOPE AND GEORGE M. MACKENZIE 



afterwards, sensitization was inhibited. This holds both for active and 

 passive sensitization. Thus, dog serum in quantities of 2.00 c.c. to .5 c.c. 

 injected with or shortly after 0.1 c.c. of horse serum in guinea-pigs, 

 prevents active sensitization of the guinea-pig to horse serum. The ex- 

 planation is similar to that offered by Richet and his co-workers for 

 the preventive action of NaCl for in the one case there is supposed 

 to be a saturation of the cells of the body by NaCl, so as to exclude a 

 union with the anaphylactic poison, and in the other a saturation of the 

 cells of the body with one foreign protein so as to exclude the union with 

 another. 



The suggestive observation made by Henrich that treatment of guinea- 

 pigs by the X-Ray suppresses sensitization of the animal to foreign pro- 

 tein has been partially confirmed by Murphy, Hussey and Steam and 

 Nokahofa. 



The Relationship of Experimental Anaphylaxis to Diseases in Man 

 It has been quite obvious now for many years that anaphylaxis, as de- 

 veloped experimentally in the animal, has an important bearing in ex- 

 plaining either directly or by analogy a number of pathological conditions 

 and states in the human being. Indeed, interest was first awakened in 

 this subject by the complete studies of von Pirquet and Schick on serum 

 disease. Later, during the development of the experimental investiga- 

 tions upon anaphylaxis, the symptoms presenting themselves in animals 

 suggested to a number of observers analogies to disease states in man, 

 the origin of which had hitherto been very obscure or unknown. It has 

 thus come about that certain cases of asthma, hay-fever, urticaria, angio- 

 neurotic edema, acute gastro-intestinal disturbances and idiosyncrasies to 

 certain foods and drugs are considered as manifestations of anaphylaxis 

 in the human being. 



It is not our object to discuss in detail evidence which has been brought 

 forward to uphold these views nor to present the clinical features of these 

 common disorders that have been so frequently and so accurately described, 

 nor indeed to present a complete account and analysis of the methods em- 

 ployed in determining the substance to which these patients may be hyper- 

 sensitive. It is, however, necessary to record to some extent the meta- 

 bolic disturbances that have been observed under the above conditions in 

 the human being and to compare in a general way, first, the definite dis- 

 ease, serum sickness, and secondly, the more obscure conditions grouped 

 together under the term "idiosyncrasies," with experimental anaphy- 

 laxis in animals and with the analogous disturbances brought about by 

 intoxication by poisonous derivatives of protein hydrolysis such as the 

 proteose's and histamin. 



Serum disease itself has no definite prototype in the experimental 

 anaphylaxis of animals. The clinical picture in the human being has 



