288 Fische/ s Theory of Edema [Dec. 



Such chemical edenias are of more than academic interest. Inas- 



much as we find in the list of poisons enumerated above, heart poisons, 



kidney poisons, nerve poisons, poisons that increase or decrease blood 



pressure, that increase or decrease lymph flow, that injure bloodvessel 



walls, or have not been proved to do so, etc., do we not, first of all, 



seriously question every theory of edema that would establish any one 



or all of these conditions as the primary cause of all edemas ? Secondly, 



these chemical edemas have interesting clinical parallels. The edema of 



arsenic poisoning and of poisoning by certain other metals is a well- 



known condition. We are also able to understand how, after the ad- 



ministration of morphin, Chloroform, ether, and alcohol (save in small 



amounts), a certain degree of edema may develop, or at least a fall in 



urinary secretion and an increased thirst be noted. All these substances 



make for a lack of oxygen and an abnormal production of acids in the 



tissues. At least part of the efTects of these various substances may, 



therefore, be satisfactorily explained through their effect upon the 



tissues generally, whereby these become edematous. Associated with 



this there must be a fall in urinary secretion and thirst. A final question 



of interest in connection with these chemical edemas (with which we 



must class the edema of kidney disease) is the distribution of the edema 



in clinical cases. These chemical edemas are always more general, and, 



as is well known, are particularly liable to first afTect the connective 



tissues of the face, particularly the eyelids. Other things being equal 



we would expect in a general intoxication those tissues which are most 



capable of swelling to be the first to give ocular evidence of the exist- 



ence of an edema. It is interesting, therefore, that of the various tissues 



examined in this regard I found the connective tissues of the orbit not 



only to be possessed of colloids most sensitive to low concentrations of 



acid, but also to have, weight for weight, the greatest affinity (' specific 



affinity') for water. (Page 126.) 



The edema of special organs. Fischer discusses the edema of 

 special organs (pp. 127-155) and the adequacy of his theory for 

 the explanation of glaucoma and edemas of the kidney, liver, and 

 lung. 



Enucleated eyes swell and rupture when immersed for a short 

 time in acid Solutions of appropriate character and concentration. 



The most intense grades of glaucoma can be induced experimentally 

 in an eye in the entire absence of any circulation (p. 127). This in- 

 creased absorption of water by the eye is dependent upon the colloids in 



