STUDIES OX THE METABOLISM OF PHOSPHORUS IN ANIMALS 



155 



llio phosphorus present in the different bodily organs and that present 

 in the blood. A part of the latter finds its way, when the digestive fluids 

 are formed, into llie intestinal tract and is thus added to the faeces. 

 The following experiment permits us to distinguish between food phos- 

 phorus and that originating from the blood. We add a known amount 

 of radioactive phosphorus to the diet and determine what percentage 

 of the latter is to be found in the faeces. In a separate experiment we 

 inject a known amount of radioactive phosphorus (sodium phosphate) 

 into the blood and determine what part of this phosphorus appears 

 in the faeces. The combination of the two results enables us to deter- 

 mine what part of the phosphorus found in the faeces is due to incomplete 

 digestion of the food eaten. 



In Table 1 the amount of radioactive phosphorus eliminated through 

 the kidneys and the gut is given for the case of a patient fed on a normal 

 hospital diet to which 0.5 mgm of labelled sodium phosphate was 

 added. Within 5 days 21.7 per cent of the phosphorus was eliminated 



Table 1. — Radioactive Phosphorx's givex to 

 HriiAN- Si'B.TECT Per Os 



in the urine and 15.5 per cent in the faeces. Similar results were obtained 

 in other cases. Table 2 shows the results obtained when the radioactive 

 ])hosphorus was injected into the blood of the same patient. Within 

 days 20.5 per cent was lost through the kidneys and 2.5 per cent through 

 the gut. Thus about 1/8 of the phosphorus atoms eliminated from the 

 blood pass through the gut. By combining the above results it follows 



