322 A CHEMICO-PHYSIOLOGICAL STUDY OF 



cleavage of egg-albumin in the preparation of antialbumid the 

 more easily decomposable half of the proteid molecule would 

 be at once eliminated. Consequently in forming antipeptone 

 from pure antialbumid by trypsin-proteolysis it is quite pos- 

 sible that the resultant peptone is free from the objectionable 

 features of ordinary antipeptone, owing to the nature of the 

 mother substance. If such is the case our present experi- 

 ments possess a double value. In partial justification of the 

 belief that antipeptone prepared from antialbumid is less liable 

 to contain the impurities referred to is the fact that the well 

 known bodies leucin and tyrosin, so common among the pro- 

 ducts formed in the breaking down of the native proteid with 

 trypsin and usually associated with the nitrogenous bases, are 

 never found in the proteolysis of pure antialbumid. Further 

 in the original analyses of antipeptone made by Kiihne and 

 Chittenden,* it was found that purification by phosphotung- 

 stic acid tended to raise decidedly the content of nitrogen ; a 

 fact which Kutscher explains by assuming the more complete 

 precipitation of the nitrogenous bases by this reagent. Thus, 

 in a preparation of fibrin-antipeptone containing 16.58 per cent 

 of nitrogen, precipitation by phosphotungstic acid resulted in 

 raising the content of nitrogen in the substance to 18.28 per 

 cent-f In other words, this method of purification led, accord- 

 ing to Kutscher, to an increase in the proportion of impurities. 

 This being so, the higher content of nitrogen in an antipep- 

 tone is to be looked upon with suspicion. Accepting the 

 truth of this statement, the extremely low content of nitrogen 

 in the antipeptone from antialbumid (13.58 per cent) may per- 

 haps be taken as additional evidence of the freedom of the 

 peptone from the objectionable nitrogenous bases. It is not 

 to be understood from this hypothesis that the anti bodies, 

 antialbumid or antipeptone, will not yield nitrogenous bases 

 on decomposition. The real distinction between a hemi and 

 anti body is based upon the behavior of the substance toward 

 trypsin. As we have already pointed out, antialbumid, which 



* Kiihne and Chittenden, Zeitschr. f. Biologic, 1886, xxii, p. 486. 

 t Kiihne and Chittenden, loc. cit., p. 452. 



