178 PROTEIN POISONS 



cells functioning in respiration. It is not unreasonable to 

 hope that a further separation of the poisonous fraction 

 into its components and a more intimate study of their 

 various actions on the animal economy may furnish valuable 

 clues not only to the relation of these chemical substances 

 to true anaphylactic processes, but also to the physiological 

 nature of the varied phenomena of hypersensitiveness." 

 It seems to us, theoretically, that there must be a whole 

 spectrum of poisons in the protein molecule. We have 

 shown that at least one group in this molecule is poisonous. 

 The poisonous action of the protein molecule becomes 

 more marked as we proceed in stripping off certain side 

 chains. Peptone is more poisonous than the native protein 

 from which it is obtained. Our product is more active 

 than peptone. Between the two there must be a group of 

 bodies, each of which is more active than the peptone and 

 less active than our split product. Indeed, we are con- 

 fident that we have discovered some of these intermediate 

 bodies. As has been stated, when the alcohol employed 

 in the cleavage of the protein molecule is not absolute we 

 obtain products that are quite unlike our poison in physical, 

 chemical, and physiological properties. They are sticky 

 and gummy. They contain some carbohydrate, responding 

 to the Molisch test, and yielding a reducing substance 

 after prolonged boiling with dilute mineral acid; while our 

 final product is not gummy and fails to show any evidence 

 of carbohydrate content, except in that from tubercle 

 bacilli. These other bodies kill much less promptly. The 

 paralytic symptoms are more marked, and the convulsive 

 stage is either only slightly in evidence or wholly wanting. 



Interesting experiments on sensitization to tuberculo- 

 protein have been made by Baldwin 1 and Krause. 2 We 

 make the following extracts from this work: Animals may 

 be sensitized by any of the ordinary products of the tubercle 

 bacillus. Sensitization may be secured by introducing 

 the protein by any parenteral route, by the peritoneal 



1 Jour. Med. Research, 1910, xxii, 189. 2 Ibid., xxii, 275; xxiv, 361. 



