94 BULLETII^ 433, U. S. DEPARTMENT OP AGRICULTUEE. 



in the soluble organic form than did the material used in any of the 

 other experiments.^ 



If each of these groups be considered separately, and Experiment 

 No. 6 be omitted from the second group because of its lower storage 

 temperature, it will be seen that, in general, the cleavage of soluble 

 organic phosphorus increases as the period of storage is lengthened. 

 If Experiment No. 6, with its 54-day storage period, is compared with 

 Experiment No. 3, with its 4:2-day storage period, it will be seen that 

 the cleavage seems to be retarded by a reduction of the storage tem- 

 perature. If Experiments Nos. 2 and 4 are compared with Experi- 

 ments Nos. 1, 3, 5, and 7 it will be seen that, proportionately to the 

 time of storage, the cleavage is less where the fresh material is com- 

 paratively rich in inorganic phosphorus and poor in soluble organic 

 phosphorus than where the reverse is the case. This latter observa- 

 tion is in harmony with the results obtained in the autolj'^sis experi- 

 ment, where it was found that the rate of cleavage of soluble organic 

 phosphorus grew less as the amount of soluble organic phosphorus 

 diminished, (In the discussion of this constituent and the fol- 

 lowing, the data referred to are those contained in the last table of 

 each experiment, and the changes referred to are those obtained by 

 subtracting the figures for the stored quarter from those for the fresh 

 quarter or vice versa. The reason for making the comparison in this 

 way has been previously indicated.) 



Inorganic 'phosphorus. — The changes in inorganic phosphorus that 

 occurred during the storage of the beef appear to have been influ- 

 enced by the same factors that influenced the changes in soluble 

 organic phosphorus, viz, the length of the storage period, the temper- 

 ature of storage, and the distribution of organic and inorganic phos- 

 phorus in the fresh material. The factors that retarded the cleavage 

 of soluble organic phosphorus, of course, also retarded the formation 

 of inorganic phosphorus; and the factors that accelerated the one 

 accelerated the other. The principal difference between the changes 

 that occurred in soluble inorganic and in soluble organic phosphorus 

 is that the amount of the first increased, while that of the second 

 decreased. Likewise, the changes in soluble inorganic phosphorus 

 afford a somewhat better idea of the phosphorous cleavage that takes 

 place during cold storage than do the corresponding changes in 

 soluble organic phosphorus, since the inorganic phosphorus is an end 

 product and is not affected by the irregular changes in the solubility 

 of the organic phosphorous compounds. 



It is not clear from these experiments whether the inorganic phos- 

 phorus that was formed during storage was derived from phos- 

 phatides, nucleoproteins, phosphocarnic acid, or other organic phos- 

 phorous compounds. Undoubtedly, however, it resulted chiefly 

 through enzymatic activity, although the particular enzyms that 

 were concerned in its production are not indicated with certainty. 

 Presumably, however, the phosphonucleases were less concerned 

 than were the phosphatases. 



Refractive indices. — The fats from the beef stored for the shorter 

 periods showed practically no changes in their refractive indices, 

 while the fats from the beef which had been stored for 74 and 177 

 days showed appreciable decreases in those values that are to be 



^ Experiment No. 7 in reality forms a third group, less than midway between the other 

 two. This distinction, however, has not been made in order to avoid complicatiBg the 

 subsequent discussion. 



