THE NUTRITIVE SALTS OF FOOD. 409 



in many respects from organic substances. When the latter are de- 

 composed, the residuum cannot be utilized by animals, and must con- 

 sequently be evacuated. Not so with the salts, which, according to 

 Voit, are not transformed. This view will not pass unchallenged, 

 when we call to mind the later researches of W. Marcet with regard to 

 the constitution of muscular tissue, wherein the English physiologist 

 has found that the phosphates enter into the nutritive process in the 

 colloid state, but quit it in the crystalloid state. 



Klein and Verson, according to Prof. Yoit, have claimed that 

 common salt is not a nutritive salt, but a mere condiment, and that it 

 may be altogether wanting in the body without inconvenience. These 

 two gentlemen lived for eight days, consuming the while only 1.4 

 gramme of salt per day, without experiencing any indisposition. 

 They, in fact, threw off, in the eight days, 46.9 grammes of chloride of 

 sodium in the liquid and solid excreta ; but we have to observe that 

 they had been in the habit of consuming salt very freely (about 27 

 grammes per day). Still the common salt in the system was not ex- 

 hausted. 



Voit states, in a note, that in the case of dogs which have the 

 normal supply of nitrogen, the addition of common salt to their food 

 increases the amount of urine, as also the proportion of water in the 

 same. Klein and Verson thought that, when they are deprived of this 

 salt, the urine must decrease ; whereas they found, on the contrary, 

 that it increased. The salt only excites indirectly the increase of 

 urine, by promoting the transformation of the albumen ; and it may 

 well be that, when the supply of salt is deficient, this transformation 

 is similarly accelerated by other influences. Klein and Verson have 

 not determined what are the necessary conditions for recognizing the 

 action of any substance in this respect. We cannot tell whether or 

 not the nitrogenous elements of the food, during their experiments, 

 were a constant quantity, for they say " taking about 420 grammes 

 of beef, etc." Nor could they say whether the nitrogen in their 

 system was in normal quantity. But, aside from this, I do not find 

 that an increased quantity of urine is by their figures shown to follow 

 the privation of salt. 



After reciting- the facts which are ascertained with regard to the 

 use of salt by domestic animals, the author adds that the constituent 

 salts of the organs, of which we spoke above, are as necessary for the 

 support of the organism as albumen, water, or the organic non-nitro- 

 genous elements ; but that, notwithstanding, no symptoms of scurvy 

 or of disease in the bones is observable, even where animals are for a 

 long period deprived of salt. He calls particular attention to this 

 fact : Kemmerich, on one occasion, gave a dog during seventeen days 

 the residuum of meat, with the salts of potash only, that is, the phos- 

 phate of potash and the chloride of potassium. He had deprived the 

 food of its salts of soda. And yet the serum of the blood was found 



