180 ANTI-ANAPHYLACTIC TREATMENT OF DISEASES 



ment, urea fell to 15 per cent. As the ammonia did not 

 increase, the conclusion is that the urine contains a new 

 substance. This new substance (X) deserves the name of 

 preurea, because if the urine stands for twenty-four hours, 

 the quantity of urea increases up to a double amount. 



"In making the same analyses of the urine of these dogs 

 affected with depressive manifestations, an increase of 

 ammonia is observed, but no substance X is found. The 

 conclusion was therefore arrived at, that if the ammonia 

 from the amino-acids is transformed rapidly into X, 

 phenomena of excitation appear; if it is transformed only 

 slowly, depressive manifestations predominate. 



"The substance X, which might be the cause of tetany, 

 is normally transformed into urea by the parathyroid glands, 

 and this fact explains perfectly the role of these glands in 

 the development of nervous manifestations. But in which 

 organ is the ammonia transformed into X (preurea)? 

 Kendall supposes that it is in the suprarenals, because the 

 removal of these glands results in depressive phenomena. 



"To verify this hypothesis, he made the following experi- 

 ment: He removed the cortical layer of the suprarenal of 

 an etherized cat, and submitted it to digestion with ammo- 

 nium carbonate. This salt was transformed into a special 

 substance different from urea. In repeating the experiment 

 with suprarenals taken from cattle or from other cats, the 

 result was absolutely negative; the ammonium carbonate 

 remained intact. 



"For a time Kendall was unable to understand the cause 

 of these contradictions. Suddenly he remembered that 

 before being etherized, the first cat had been for some time 

 in the presence of two dogs which had terrorized it. This 

 was a flash of light. The ferment which transforms the 

 ammonia into preurea must be produced by the influence of 

 nervous excitation. He resumed his experiments on cats 

 previously frightened, and found again in the cortex of the 

 suprarenal the ferment he was looking for. He also obtained 

 a positive result, not however constantly, by submitting the 

 suprarenals to the action of an electric current. 



"Besides nervous influences, one must always consider 



