Page:Popular Science Monthly Volume 1.djvu/421

Rh 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 Kemmerich; 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 residuum 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 [sic] 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. Zörster 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. Consequently 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 considerable 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