PROTEIN SENSITIZATION OR ANAPHYLAXIS 295 



of pathological conditions. It is probable that under normal 

 conditions the liver can deal adequately with /3-i, as it 

 can with the amins of tyrosin and tryptophan, and render 

 it innocuous; but if this defensive mechanism of the liver 

 breaks down for any reason, then many toxic symptoms 

 will no doubt follow. For instance, one of us has elsewhere 

 suggested that the condition of cyclic vomiting in children 

 may be due to the excessive accumulation of such sub- 

 stances as fi-i in the intestine, causing, from time to time, 

 an exacerbation of symptoms. In any case a fact which 

 would appear to point to means of lessening the formation 

 of this substance in the alimentary canal is worth consid- 

 eration. This base is not produced in an acid medium, and 

 this fact is additional support to the medical treatment, 

 as advocated by Metchnikoff, involving the injection of 

 lactic acid producing bacilli. It is necessary, however, 

 to point out that the colon bacillus responsible for the 

 production of the toxic product is not killed by the acidity 

 of a medium, but its energies are only directed along other 

 lines, so that as soon as an alkaline reaction returns the 

 production of the histidin base continues." 



The Kyrins. These bodies have been studied and described 

 by Siegfried, 1 who regards them as intermediate products 

 between the proteins and the amino acids. His method 

 of preparation consists in digesting the protein (fibrin, 

 casein, etc.) for three weeks at 3S to 39, with from 12 to 

 16 per cent, hydrochloric acid. This mixture is filtered 

 and the filtrate precipitated with phosphomolybdic acid. 

 The precipitate is extracted with dilute sulphuric acid 

 and precipitated with alcohol. Solution and precipitation 

 with these reagents are repeated about fifteen times, but 

 after the ninth a substance of constant composition is 

 secured, and this is a kyrin. With the cleavage process 

 carried one step farther these bodies are converted into 

 amino acids. It will be seen from the method of preparation 

 that they are closely related to the diamino acids (arginin 



itsch. f. physiol. Chem., 1906, xlviii, 54. 



