METABOLISM. 487 



pxybutyric, which can be detected in the urine. Acetone is also 

 present in the urine of severely diseased diabetics. 



Phosphorus. Phosphorus is found in all the cells in the shape 

 of lecithin, a nucleo-proteid. 



The pathway of elimination of phosphorus is mainly in the fa3ces. 

 Phosphorus can be supplied to the body both in inorganic and organic 

 combinations, as both compounds can be absorbed from the intestines. 

 The average daily quantity of phosphorus needed is about two 

 grams. 



If the supply of phosphoric acid is not sufficient the body is not 

 able to limit the excretion of phosphoric acid to the same extent as is 

 possible in the case of chlorine under similar conditions. In fasting 

 the body gives off phosphoric acid until the end. The muscles of the 

 body contain nitrogen and phosphoric acid in certain proportions. A 

 certain relation exists between the progress of excretion of nitrogen 

 and of phosphorus. 



In man's muscles the relation between nitrogen and phosphoric 

 acid is about as follows : 



N 100 N 



= 7.3; or, 



P 2 5 13.7 P 



Calcium and Magnesium. These bodies are excreted and absorbed 

 by the intestines as inorganic compounds. In the faces there is an 

 average of 0.16 grams of calcium and 0.06 grams of magnesium 

 per day. Tigerstedt calculates that a daily supply of 0.3-0.7 grams 

 of calcium and of about 0.4 grams of magnesium is necessary. 



Lime is abundant in cartilage and bone. Magnesium predomi- 

 nates in the blood-corpuscles. In the infant much lime furnished by 

 the milk is used in the development of the skeleton. 



Lime occurs in large amount in milk. The only other food 

 which has the same amount as milk is the yelk of egg. This latter 

 should be given to children when milk is not at hand or not readily 

 digested. Calcium is excreted chiefly with the succus entericus. 



Eickets follows when there is not sufficient calcium in the food, 

 and also in cases where calcium is sufficient but the cells of the bone 

 and tissue cannot assimilate the lime. 



The alkaline earths, if in too great quantity, may precipitate and 

 form hepatic calculi. 



Chlorine, Fluorine and Iodine. Chlorine is found in all the 

 tissues, united with potassium, sodium and calcium. Hydrochloric 

 acid is an element in the gastric juice. Fluorine exists in bone and 

 the yelk of eggs. Iodine exists in the thyroid gland as iodothyrin. 



