THE NUTRITIVE SALTS OF FOOD. 407 



true, but his condition was pitiable. He could hardly walk ; his eyes 

 were dull and expressionless; his body appeared emaciated, and he 

 took his food reluctantly and without relish. 



Voit here makes an objection to the conclusions drawn by Kem- 

 merich ; but his objection is not valid, because he does not advert to 

 the fact that the dogs in question, owing to their age, must necessarily 

 gain considerably in weight. His objection would hold good only in 

 the case of full-grown animals. However, to remove all doubt as to the 

 increase of weight when the salts of meat are added to the residuum, 

 Kemmerich gave the second dog the residuum with these salts ; and 

 to the first dog the same, with table-salt only ; the quantity of residu- 

 um being in both cases equal. The result was, that the dog which had 

 before got only common salt, now gained much faster than the other, 

 which latter, however, gained 530 grammes in thirty-two days. 



There is no need to give in full Voit's argument on the results of 

 Kemmerich's experiments. It is enough for us to state, with Voit, 

 that these experiments demonstrate the fact that a carnivorous animal 

 can live on meat-residuum, provided that there be added to it the salts 

 of meat and common salt. Still, these experiments do not answer the 

 principal questions we have put, viz., How long can an adult organism 

 live without salts ? and, What are the symptoms they manifest, when 

 thus deprived ? So the attempt was made to study, in adult animals, 

 the changes that occur in albuminoid substances, when the salts are 

 extracted. 



Dr. J. Zorster made the experiments. The purpose was to sustain 

 animal life as long as it was possible, on food very poor in salts. The 

 animals experimented upon were never given albuminous substances 

 alone, but always mixed with a sufficient quantity of non-nitrogenous 

 elements, such as fat, starch, or sugar. The albuminate employed was 

 the residuum of meat dried in the oven, pulverized, and then boiled 

 three times in water. Cheese, also, deprived of the salts, was given. 

 Pigeons and mice took this food, in small morsels, for some time. 

 Dogs also took it for a short time, but then refused it. Then they 

 were compelled to take it. The mice lived from twenty-one to thirty 

 days ; the pigeons from thirteen to twenty-nine days ; the dogs from 

 twenty-six to thirty-six days. 



Digestion went on regularly for the greater part of the time. The 

 excreta, whether in quantity or in quality, were as usual. Conse- 

 quently neither the process of digestion, nor the absorption of the 

 materials digested, is influenced by the absence of salts from the food. 

 In the case of a dog with a gastric fistula, fed on food deprived of the 

 salts, direct evidence was obtained of the fact that the secretion of 

 acids in the stomach goes on. After having been kept for a consider- 

 able period on this diet, the dog commenced to reject it from his 

 stomach. What was thus rejected, though it had been in the stomach 

 several hours, was not soured, nor had it the least unpleasant odor. It 



