I4OO FKEUS AND FKKDING 



table and animal origin (hominy, which consists of decorticated and germ 

 free maize grains, blood albumen, wheat gluten, maize bran, and agar-agar) 

 to which the phosphorus compounds have been added in the form of almost 

 chemically pure substances. All the rations also contain sodium chloride. 

 The writers have noted that the results cannot be extended to the same com- 

 pounds when found in foods under natural conditions. Moreover it is stat- 

 ed that according to the literature the lecithins and phosphoproteins (not 

 included in these experiments) have higher nutritive values than all the 

 compounds here studied, i. e. phosphates, hypophosphites, nucleic acid, 

 phytin and the glycerophosphates. 



Five experiments were made. The first (April and May 1908) consis- 

 ted of a metabolism experiment lasting ten days raade with four pigs ; the 

 second (November to December 1908) consisted of a feeding experiment 

 (56 days) and analyses of the carcases (30 pigs) ; the third and fourth (No- 

 vember 1909 to January 1910) were of the same type as the second and were 

 performed with 35 and 45 pigs respectively ; lastly the fifth (March to June 

 1913) was a carefully controlled series of experiments of metabolic equili- 

 brium for the comparison of glycerophosphates and phosphates which was 

 completed with a slaughter test and the thorough chemical study of the car- 

 cases of the six subjects experimented with. 



The results are given in numerous comprehensive tables and are sum- 

 marised and discussed in the following manner. 



The results of experiment I show clearly that the phosphorus of ortho- 

 phosphates, hypophosphites and the nucleic acid of beer-j^east, added in a 

 pure state to rations poor in phosphorus but capable of maintaining the 

 phosphorus equilibrium, can be absorbed by pigs and retained in the or- 

 ganism in considerable quantities for at least ten days. It has certainly 

 not been proved that each of these compounds can be permanently retained, 

 but that seems quite probable. In the case of the hypophosphites this would 

 necessitate a further oxidation of the phosphorus to the form of orthopho - 

 phate. 



In the conditions of experiments II, III and IV', some results suggest 

 that, from a nutritive point of view, the glycerophosphates would be superior 

 to the orthophosphates, nucleic acid, phytin and hypophosphites, especialh' 

 in respect to the proportion of muscular tissue and fat in the increase of 

 live weight, and the breaking strength of the bones and their ash-content 

 per cubic centimetre ; but the facts are not sufficiently concordant to estab- 

 lish this conclusion firmly. 



It is concluded from the results of experiment IV that the mineral con- 

 stituents and the ethereal extract of the blood are notabh^ affected by the 

 diet, which also modifies considerably the salts composing the bones, both 

 as to their quantity and their relative proportions. 



Experiment V gave a ver^^ uniform and consistent series of observations 

 of different kinds, proving that, anyway in the artificial conditions of this 

 experiment, there are no essential differences in the mineral metabolism, 

 the digestibility' of the food, and the amount and composition of the growth 

 of swine, as affected by phosphates and glycerophosphates. It seemb 



