104. Report oF DEPARTMENT OF ANIMAL HUSBANDRY OF THE 
during two periods of four days each, one with an excess and 
the other with a deficiency, of phosphorus compounds in the ration. 
The unlike results in the two periods appear to be significant in 
their relation to the supply of phosphorus compounds. During the 
period of low phosphorus supply the withdrawal of calcium com- 
pounds from the body store was greatly increased, with a some- | 
what corresponding increase in the storage of potassium oxide. 
There was a storage of magnesium oxide in both the high and low 
‘phosphorus periods, this being considerably greater in the former. 
These facts would indicate that there was a replacement of calcium 
oxide by another base, particularly in the period of low phosphorus 
feeding. On the other hand the greatly increased excretion of 
calcium compounds in the low phosphorus period suggests a cleav- 
age of calcium compounds in some way connected with the defi- 
ciency of phosphorus in the food, the most natural inference being 
that the egested phosphorus not supplied by the food was obtained 
from a body compound containing calcium oxide as a base. 
The metabolism and excretion of phosphorus and other mineral 
compounds of the food.—It has been shown that the phosphorus 
of the catabolized phytin and nucleo-proteids appears in inorganic 
combinations mostly in the feces, though to some extent in the 
urine, and that the calcium oxide which is withdrawn from the 
body store is excreted in a quite similar-manner. These are facts 
of general physiological interest and are confirmatory of the ob- 
servations made by other investigators. 
The question as to where the cleavage of the compounds under 
consideration takes place is an interesting one. In order to throw 
light on this problem we have studied the action of trypsin and 
pepsin on the free acid of phytin and its simple salts without 
securing evidence of the power of these enzyms to split these 
bodies into inorganic forms. To be sure, the influence of other 
enzyms such as erepsin and of bacterial ferments has not been 
tested and so we have no direct proof that these latter might not 
effect a cleavage of the phosphorus bodies we are studying, but this 
hardly seems probable. 
It is certain that phytin entirely disappeared from the intestinal 
tract and did not reappear even in small proportions in the milk or 
urine. By our methods of analysis it is possible to determine very 
