Sect. II.] Physiology. 305 



and in wooden tubes, perforated in such a manner 

 as to admit the entrance of the gastric juice ; these 

 he swallowed ]iimself,and, after a short interval, the 

 contents of them were found to he dissolved and 

 discharged. He satisfied himself that no tritura- 

 tion could take place by employing tubes so thin 

 and weak that the slightest pressure would have 

 crushed them to pieces; yet not one was ever 

 broken, nor could he ever perceive the snuillest de- 

 pression or fissure. Of the active solvent ]>o\vers 

 of this gastric fluid he gives many remarkable 

 proofs. In a dog it not only dissolved bones, but 

 was found to corrode the enamel of two dcntcs in- 

 cisor es taken from the jaw of a sheep. And, from 

 some experiments on himself, he observed it to be 

 sufficiently powerful to digest not only muscular 

 fibres and meml>ranes, but tendon, cartilage, and 

 even bone itself, when not of the hardest kind. 



The conclusions arising from these experiments 

 of the professor of Pavia were, about the same time, 

 confirmed aiKl illustrated by others equally inge- 

 nious and interesting, undertaken by Dr. Edward 

 Stevens*. He prevailed on a person to swallow 

 little hollow spheres of silver, filled with food of 

 different kinds ; the sides of the spheres being per- 

 forated in various places, the gastric juice had ac- 

 cess to, and, of course, could act upon their con- 

 tents; and when voided, the food within them was 

 found to be dissolved, either partially or entirely, 

 according to the nature of it, and the time allowed 

 for its remaining in the stomach. 



*-See his Inmigural Dissertation. publi.sl:^'d at Kdiiiburgh, m 

 the yeai' 1777- 



