ALKALINE PHOSPHATES. . 445 



porate the filtered fluid, again extract with spirit, and dissolve the 

 residue in water, the aqueous solution only seldom exhibits any traces 

 of sulphates. That sulphate of soda is frequently found even in con- 

 siderable quantity in the ash of these animal fluids, and indeed that 

 it must be found there, is sufficiently explained by the remarks we 

 have already made regarding the changes which the mineral consti- 

 tuents of animal substances undergo on incineration. The bile 

 presents one of the best examples of these changes, for its ash is 

 very rich in sulphates, while we can hardly discover a trace of them 

 in the fresh fluid. 



The frequent use of the alkaline sulphates in medicine might 

 almost lead to the presumption, that these salts when conveyed 

 into the system with the food, are not devoid of use in relation to 

 the physiological functions of the animal organism, and in particu- 

 lar to that of digestion. When on the one hand we take into 

 consideration the changes which the alkaline sulphates undergo in 

 the process of digestion, and, on the other, the occurrence of highly 

 sulphuretted organic substances in the animal organism, great prob- 

 ability seems to attach to this view. The experience of physicians, 

 and direct physiologico-chemical experiments have clearly proved, 

 that small quantities of alkaline sulphates are converted in the 

 intestinal canal during digestion into sulphides. Hence we might 

 conclude that these salts take part in the production of such highly 

 sulphuretted animal substances as taurocholic acid, horny tissue, 

 &c., but as substances which contain sulphur, such as legumin, glu- 

 ten, &c., enter the animal body with the vegetable food, these highly 

 sulphuretted substances, peculiar to the animal body, might also 

 derive this element from the non-oxidised sulphur of the food. In 

 the absence of any decisive experiments in favour of either of these 

 views, we must for the present leave this question unanswered. 



The experiments of Laveran and Millon* have shown that it 

 is only when taken in large doses that the alkaline sulphates are 

 carried off in the stools, small doses being absorbed in the intes- 

 tinal canal and eliminated by the kidneys. We should, however, 

 be in error, if we assumed, as Laveran and Millon seem to do, that 

 this salt is simply absorbed in the intestinal canal; for it is well 

 known that, after the use of alkaline sulphates, there is an exces- 

 sive development of intestinal gas, which is especially rich in sul- 

 phuretted hydrogen. 



This conversion of the sulphates into sulphides in the intestine 

 during digestion is further established by the following facts. L 

 * Ann. d. Chim. et de Phys. T. 12, p. 135. 



