1913] Jacoh Shulansky and William J. des 53 



The data in Table 4 suggest that the protein of the meat inter- 

 fered with complete liberation of the ammonium nitrogen from the 

 very large proportions of triple phosphate present in each case, but 

 the probabihty of overcalculation of the amounts of ammonium ni- 

 trogen in the mixtures is against that indication. (See footnote. 

 Table 4. ) The data in Table 4 also suggest that ammonia was not 

 produced from the protein of the meat. 



3. General conclusions. Ignoring, for the present, certain 

 considerations which the senior author intends to discuss in a sub- 

 sequent issue of the Biochemical Bulletin^ we conclude that the 

 NaOH-NaCl method for the determination of ammonium nitrogen 

 in meat is more accurate than the NagCOs-NaCl process. This 

 greater degree of accuracy we attribute to the capacity of the 

 NaOH-NaCl method to eject, as ammonia, all the nitrogen in 

 ammonio-magnesium phosphate, whether crystallized or dissolved. 

 It is evident, also, that the NaOH-NaCl method is particularly 

 suitable for the study of meat subjected continuously to prolonged 

 periods of cold storage, because of the completeness with which the 

 nitrogen of ammonio-magnesium phosphate may be removed and ob- 

 tained as ammonia, and because any deficiencies of the method, espe- 

 cially as compared with the NasCOg-NaCl process, induce plus 

 errors — errors of the kind that would tend to suggest putrefactive 

 changes very early, if any such changes were in progress. 



The ammonia determinations in the work on fish described by 

 Smith^^ and by Perlzweig and Gies,^^ in the two succeeding papers, 

 were based on these findings. Their results with the NaOH-NaCl 

 method give special emphasis to the foregoing conclusions. 



[The preceding paper by Benedict,^^ which was received on the 

 day the manuscript of this number of the Bulletin was forwarded 

 to the printer, also has an important bearing on these deduc- 

 tions. Ed.'\ 



11 Smith : Biochemical Bulletin, 1913, iii, p. 54. 



12 Perlzweig and Gies : Ibid., p. 69. 



13 Benedict and Osterberg: Ibid., p. 41. 



