ANIMAL PEODUCTION. 169 



At the end of the period the ral)bits and also 2 uoruial rabbits were chloro- 

 formed and the different orpins of tlie body analyzed. In all cases post-mortem 

 examinations were made and slides of the various organs were made and 

 histological changes noted. 



The i)reliminary feeding ])(>riod lasted !(»('' days, with the following resnlts: 

 One rabbit that received a larger amount of nitrogen than the others gained 

 in weight. The total nitx'ogen ingested varied during a period of 7 days fvom 

 5 to (5.6 gni. of nitrogen per 1,000 gm. of body weiglit. More nitrogen was 

 excreted in the urine of those fed orgaiuc jiliosphorns tlian in the case of tliose 

 fed inorgaiiic phospliorus. The amount of nitrogen eliminated in the feces 

 varied with the individual rabbit from 9.3 to 14.6 per cent. The rabbits fed 

 inorganic phosphorus retained a larger proportion of the absorbed nitrogen 

 than did those fed organic phosphorus. The average amount of phosphoric acid 

 ingested during 7 days per 1,000 gm. of body weight varied from 1.6 to 2.2 

 gm. From the average tigures it appears that the rabbits fed organic phos- 

 phorus eliminated a smaller percentage of the ingested phosphoric acid in the 

 urine than those fed on inorganic phosphorus. The ratio of nitrogen to 

 phosphoric acid in the food was but slightly above 3 : 1, a much larger propor- 

 tion of phosphoric acid than is usually fed in a normal diet. The ratio of 

 nitrogen to phosphoric acid in the urine varied from 5: 1 to 7.5: 1, being higher 

 in the case of the rabbits fed organic phosphorus owing to the rebitively larger 

 elimination of phosphoric acid in the urine of those fed inorganic phosphorus. 



The pi-incipal feeding period lasted 4 weeks. The amount of nitrogen 

 ingested and absorbed was quite uniform. The amounts excreted in the urine 

 and feces varied considerably. The relation of urine nitrogen to urine phos- 

 phorus was Iiighest in the case of the rabbits fed organic phosphorus. The 

 ratio in the feces was very regular. A higher ratio of calcium to magnesium 

 was noted in the feces of the rabbits fed inorganic phosphorus. This ratio 

 varied considerably in the urine of the individual rabbits, as did also the ratio 

 of i)hosphoric acid to calcium in the feces. The phosphoric acid to calcium 

 ratios in the urine again showed more phosphorus eliminated by rabbits fed 

 inorganic phosphorus than by those fed organic phosphorus. The ether-alcohol 

 extracted phosphorus represented but a small proportion of the total organic 

 combined phcfsphorus. and it is concluded that no ether -alcohol phosphorus is 

 normally present in the urine even after the feeding of organic phosphorus. 



'• In the case of the rabbits fed organic phosphorus the average amount of cal- 

 cium absorbed from the intestinal tract or metabolized was higher than in the 

 case of those fed inorganic phosiihorus. These figures agree with the theory 

 that the calcium and phosphorus in the inorganic form unite to form the insol- 

 uble calcium phosphate which is eliminated by the bowels in an unchanged 

 form." The amount of metabolized magnesium that was retained indicates 

 that the rabbits fed inorganic phosphorus, while metabolizing a smaller amount 

 of the magnesium than did those fed organic phosphorus, retained a larger 

 percentage of the amount actually metabolized. 



A post-mortem examination of the bones of the experimental rabbits showed 

 tliat they formed a larger percentage of the body weight than in the case of 

 normal rabbits and a higher content of ether-soluble matter. The livers of the 

 rai>l)its fed on organic phosphorus for several months showed fatty degenera- 

 tion as well as fatty infiltration. Of the livers of the inorganic phosphorus-fed 

 rabl)its one showed both fatty degeneration and fatty infiltration ; the other, 

 only slightly fatty infiltration. The livers were enlarged and contained con- 

 siderably more nitrogen and phosphoric acid than normal livers when calcu- 

 lated to a water and fat-free Itasis. As com]»ared with the normal ralibits, the 

 brains and nerves of the rabbits fed on organic phosj)horus yielded a larger 

 percentage of ether-alcohol soluble jihosphorus, while those of the rabbits fed 



