LACK OF MINERAL SUBSTANCES IN THE FOOD. 843 



to the kind of combination, or whether they occur in stoichiometric 

 proportions, or whether they are simply adsorption combinations. In 

 accordance with this the organism persistently retains, with food poor 

 in salts, a part of the mineral substances, also such as are soluble, as the 

 chlorides. On the burning of the organic substances the mineral bodies 

 combined therewith are set free and may be eliminated. It is also 

 admitted that they in part combine with the new products of the com- 

 bustion, and in part with organic nutritive bodies poor in salts or nearly 

 salt-free, which are absorbed from the intestinal canal and are thus retained 

 (VoiT, FORSTER !). 



If this statement is correct, it is possible that a constant supply of 

 mineral substances with the food is not absolutely necessary, and that the 

 amount of inorganic bodies which must be administered is insignificant. 

 The question whether this be so or not has not, especially in man, been 

 sufficiently investigated; but generally we consider the need of mineral 

 substances by man as very small. It may, however, be assumed that 

 man usually takes with his food a considerable excess of mineral sub- 

 stances. 



Experiments to determine the results of an insufficient supply of 

 mineral substances with the food in animals have been made by several 

 investigators, especially FORSTER. He observed, on experimenting with 

 dogs and pigeons with food as poor as possible in mineral substances, 

 that a very suggestive disturbance of the functions of the organs, par- 

 ticularly the muscles and the nervous system, appeared, and that death 

 resulted in a short time, earlier in fact than in complete starvation. On 

 observations made upon himself, TAYLOR 2 found on partaking less than 

 0.1 gram salts per diem that the chief disturbance occurred in the mus- 

 cular system. 



BUNGE in opposition to these observations of FORSTER' s has suggested 

 that the early death in these cases was not caused by the lack of mineral 

 salts, but more likely by the lack of bases necessary to neutralize the sul- 

 phuric acid formed in the combustion of the proteins in the organism; 

 these bases must then be taken from the tissues. In accordance with 

 this view, BUNGE and LUNIN 3 also found, in experimenting with mice, 

 that animals which received nearly ash-free food with the addition of 

 sodium carbonate were kept alive twice as long as those which had the 

 same food without the sodium carbonate. Special experiments also 



1 Forster, Zeitschr. f. Biologic, 9. See also Voit in Hermann's Handbuch, 6, Part 1, 

 354. In regard to the occurrence and the behavior of the various mineral constituents 

 of the animal body see the work of Albu and Neuberg, Physiologic und Pathologic des 

 Mineralstoffwechsel, Berlin, 1906. 



2 University of California Publications, Pathol., 1. 



3 Bunge, Lehrbuch der physiol. Chem., 4. Aufl., 97; Lunin, Zeitschr. f. physiol. 

 Chem., 5. 



