460 JACOB ROSENBLOOM 



Magnesium Metabolism 



Magnesium is supplied almost exclusively in inorganic forms; its 

 resorption is less dependent than that of calcium upon the reaction in the 

 intestine. According to Renwall 29 to 34 per cent of the total magnesium 

 appears in the urine (with free choice of food 36.2 to 37 per cent). 

 According to Bunge(&) the magnesium need of the adult is at most 0.69 

 gm. per day. In 24 hours 0.14 to 0.29 gm. MgO are excreted in the urine. 



The precipitation of phosphates and carbonates with calcium and 

 magnesium takes place in neutral and alkaline urines, only seldom in 

 acid urine. 



An alkaline reaction in human urine may be the result of a vegetable 

 diet or the use of alkaline salts; that is of an exogenous origin. But an 

 alkaline reaction may occur from internal causes, as when great amounts 

 of acid are excreted in the stomach, that is, in normal circumstances, in the 

 hours of abundant gastric digestion. If the hydrochloric acid of the 

 gastric juice is lost by long continued vomiting, the stomach, whose glanc 

 possess to a high degree the ability to concentrate hydrogen ions, become 

 an excretory path for hydrogen ions, and the kidneys, in order that the 

 neutral reaction may be conserved, must give out hydrogen ions. Alkaline 

 urine and chronic HC1 vomiting stand in a causal relation so that with 

 constant vomiting a strongly acid urine is possible only with anacidity. 



If phosphate precipitation takes place in an alkaline urine produced ii 

 this way, it is not to be considered as phosphaturia. Nor do we designat 

 as phosphaturia the cloudy urine which results from ammoniacal fermen- 

 tations due to infection of the urinary tract. 



As actual endogenous phosphaturia may be reckoned only cas 

 which void cloudy, milky urine constantly or in painful attacks with nerv- 

 ous symptoms, and upon a diet which would normally produce acid urine. 

 Samples of urine with evidences of phosphaturia are frequent where 

 constant true phosphaturia is much more rarely observed. 



Endogenous phosphaturia is mostly combined with nervous or neurs 

 thenic symptoms or with disturbances of the stomach or urogenital system. 



G. Klemperer(c) attempts an etiological division of phosphaturia into 

 the following forms: 



1. Phosphaturia caused by gastric hyperchlorhydria. 



2. Phosphaturia caused by increased calcium excretion in the urine, 

 a heightened "calcium avidity of the kidney." 



3. Sexual phosphaturia. 



The changes in the urine during phosphaturia are certainly not the 

 result of an increased phosphoric acid excretion. On that point there is 

 complete unanimity. According to Minkowski the separation of a phos- 

 phate sediment is always to be regarded as an expression of diminished 

 acidity. Leo also considers the alkaline reaction as the dominant feature 



