VENOUS. 681 



M. FodeVa in support of his views will be considered under the head of 

 SECRETION. They go chiefly to show the facility with which substances 

 penetrate the parietes of vessels and other tissues of the body ; an action 

 which he found to be singularly accelerated by the galvanic influence. 

 Prussiate of potassa was injected into the cavity of the pleura; and sul- 

 phate of iron introduced into that of the peritoneum in a living animal. 

 Under ordinary circumstances, it requires five or six minutes before the 

 two substances meet by imbibition through the diaphragm ; but the ad- 

 mixture is instantaneous if the diaphragm be subjected to a slight gal- 

 vanic current. The same fact is observed, if one of the liquids be placed 

 in the urinary bladder, and the other in the abdomen; or the one in the 

 lung, and the other in the cavity of the pleura. It was further found, 

 that, according to the direction of the current, the union took place in 

 the one or the other cavity. Dr. Bostock, 1 in commenting on these 

 cases, thinks it must be admitted, that they "go very far to prove that 

 membranes, perhaps even during life, and certainly after death, before 

 their texture is visibly altered, have the power of permitting the transu- 

 dation of certain fluids." That such imbibition occurs during life, ap- 

 pears to be indisputably proved. If the clear and decisive experiments 

 of Magendie and Fod6ra were insufficient, the additional testimony, 

 afforded by Lawrence, Coates, and Harlan ; by Dutrochet, Faust, Mit- 

 chell, Rogers, Draper, and others, would command it. By the different 

 rates of penetrativeness of different fluids, and of permeability of dif- 

 ferent tissues, we can explain why imbibition may occur in one set of 

 vessels and not in another; and the constant current, established in the 

 interior of the vessel is a sufficient reply to the suggestion, that there may 

 not be the same tendency to transude after the fluid has entered it. 

 M. Adelon 2 is of opinion, that under the view of imbibition we ought 

 to find substances in the arteries and lymphatics also ; but a sufficient 

 objection to this would be, the comparative tardiness, with which the 

 former admit the action ; and the selection, and, consequently, refusal, 

 exerted by the latter; but even here evidences of adventitious imbibition 

 are occasionally met with; as in the case of salts, which we have seen 

 have been detected in the thoracic duct, after having been intro- 

 duced into the cavity of the abdomen. 



The two following experiments by Prof. J. K. Mitchell, 1 which are 

 analogous to numerous others, performed in the investigation of this 

 subject, well exhibit endosmose in living tissues. A quantity of a solution 

 of acetate of lead was thrown into the peritoneal cavity of a young cat; 

 sulphuretted hydrogen being passed, at the same time, into the rectum. 

 In four minutes, the poisonous gas killed the animal. Instantly on its 

 death, the peritoneal coat of the intestines, and the parietes of the 

 cavity in contact with them, were found lined with a metallic precipi- 

 tate, which adhered to the surface, and was removable by nitric acid 

 moderately diluted. It was the characteristic precipitate of sulphuretted 

 hydrogen, when acting on lead. In another experiment on a cat, a 

 solution of acetate of lead was placed in the thorax, and sulphuretted 

 hydrogen in the abdomen. Almost immediately after the entrance of 



1 Physiology, edit, cit., p. 629. 2 P- cit - 



3 American Journal of the Medical Sciences, vii. 44, Philada., 1830. 



