MINERAL METABOLISM 



305 



TABLE II 



other fluids, the nerves and organs. Dennstedt and Rumpf have made an 

 exhaustive study of previous work on the mineral constituents of the dif- 

 ferent organs, and from this and their own work have compiled a table (I) 

 giving what may be considered representative figures. These values are of 

 interest chiefly in that they give an idea of the comparative abundance 

 of the different elements, and they are to be considered as only approxi- 

 mately expressing the composition of any individual normal organ. There 

 are no fixed relations in the ratio of different elements to each other, and 

 variations amounting to as much as % to 2 times these average values m&y 

 be found. 



Recent work by Magnus-Levy (;) which is sinnmarized in Table II is of 

 special interest when compared with the values given above, for while the 

 analyses are calculated to a different basis they allow comparisons of the 

 relative amounts of the different elements, and show rather wide differ- 

 ences from the results of Dennstedt and Rumpf. That much of the nor- 

 mal variation may be due to variations in the fat and water content of 

 the organs, components which may vary widely under physiological con- 

 ditions, is very probable, especially in the earlier analyses. Magnus-Levy 

 has eliminated these variables by calculating to a dry, fat free basis, and 

 has probably eliminated variables due to pathological conditions, since 

 his subject was a suicide. Pathological conditions are usually char- 

 acterized by increased water and NaCI content, and by decreased Ca and P. 



In the highly specialized cells the ratio of K : IsTa is higher than in 

 supporting tissues (Gerard). In muscle, K phosphate is the predominant 

 constituent and Mg is more abundant than Ca. As the result of analyses 

 by Bunge, Aron gives the relationship of K : ]N"a in muscle as 5-6 : 1. 

 Benedict concludes that there is approximately three times as much Mg as 

 Ca in the human muscle. Heubner found 0.15 per cent P in the fresh 

 muscle of young dogs of which 70-00 per cent was water soluble (phos- 

 phates), 0.05 per cent P in the skin and 1.5 per cent P in bones. Meigs 

 and Ryan have found the smooth muscle of the frog lower in K, Mg and 



