CHANGES INt 'FRESH BEEF DURING COLD STORAGE. 93 
On account of the 'many factors that seem to influence the forma- 
tion of ammoniacal nitrogen and because of the small quantities of 
ammoniacal nitrogen found in the beef, even after long periods of 
storage, the changes in this constituent have not constituted a good 
index of the extent of autolysis in the cold-stored beef ; nor can they 
be regarded as being of any practical significance. The production 
of ammonia is probably largely due to the combined action of several 
proteolytic enzyms. 
Acidity. — The beef stored for 14, 28, and 177 days showed slight 
apparent decreases in acidity, while that stored for 42, 63, and 74 
days exhibited from slight to appreciable gains in that constituent. 
The presence of acid-forming enzyms in muscular tissue is well 
known, and the increases that took place in the acidity of the meats 
were undoubtedly due, in large part at least, to enzym action. 
Total phosphorus. — With the exception of the quarter of beef 
stored for 14 days, each cold-stored quarter contained less total 
phosphorus than the corresponding fresh quarter. This seeming 
loss of phosphorus was accompanied in every case but one by a 
corresponding loss in total nitrogen. Similar variations in total 
phosphorus and total nitrogen were observed during the autolysis 
experiment. Of themselves these data would go to show that phos- 
phorus actually was lost from the meat during storage ; yet, in view 
of the improbability of such an occurrence and the smallness of the 
apparent losses, the evidence would scarcely justify such a conclusion. 
Insoluble phosphorus was determined by difference, and what is 
stated in the following paragraph applies inversely to this constituent. 
Total soluble phosphorus. — The changes that occurred in total 
soluble phosphorus during the cold storage of the beef were of a very 
irregular nature. The changes were sometimes large and sometimes 
small, sometimes positive and sometimes negative, but in no case 
did they seem to bear any relation to any known factor. Even in 
Experiment No. 7, where the storage period was 177 days, two de- 
creases and one increase in this constituent were observed. It can 
only be inferred that the solubility of some portion of the organic 
phosphorus was influenced by some obscure factor that was not prop- 
erly controlled in these experiments, and which escaped detection in 
the autolysis experiment in consequence of the extensive cleavage of 
insoluble phosphorus. Obviously, therefore, in the present case no 
particular significance can be attached to these irregular changes. 
Soluble organic phosphorus. — The changes that have occurred in 
the soluble organic phosphorus of the beef during the storage periods 
of these experiments appear to have been influenced not only by 
the length of the storage period and by the temperature of storage, 
but also by the relative amounts of preformed soluble organic and 
inorganic phosphorus contained in the fresh material. In order that 
these relations may be studied, therefore, the experiments must be 
classified, not only with reference to the time and the temperature 
of storage, but also with regard to the initial distribution of soluble 
organic and inorganic phosphorus. In reference to the latter fac- 
tor, Experiments Nos. 2 and 4 should be placed in one group and trie 
other experiments in a second group, since the material used in Ex- 
periments Nos. 2 and 4 each contained a greater proportion of total 
phosphorus in the soluble inorganic form and a smaller proportion 
