EDEMA 165 



proportionate amounts. He has found complement in a newly formed 

 hydrocele in quantities equal to those found in inflammatory exudates. 

 Antibodies pass freely into both varieties of fluid, and Delrez has found, 

 in cases of syphilis, a positive Wassermann reaction, with the same titer 

 in edema fluid as in the blood. 



The ioxicity of edema fluids has been studied by Boy-Tcissier. 

 Transudates have been found to be without toxic action on animals. 



PART III 

 The Pathological Physiology of Edema 



From the standpoint of pathological physiology there may be con- 

 sidered : ( 1 ) the possibility of alteration in the mechanism of the entrance 

 of lymph into the lymphatics and its flow through them; (2) changes in 

 the metabolism of the tissue cells, which might influence the movement of 

 fluid; (3) changes in the permeability of the capillaries, especially in 

 conditions associated with edema; (4) circulatory changes, and (5) 

 changes in renal excretory function. It is the purpose of this section to 

 present the facts ascertained by study, leaving an analysis of their sig- 

 nificance to a later section (Part IV). 



Definition of Terms. It is necessary to define accurately the use of 

 certain terms, since there exists considerable confusion in the literature 

 with regard to them. The following definitions are adopted for use in 

 the discussions to follow. The term lymph is used only to describe the 

 contents of the lymph vessels, the term tissue fluids being used as a general 

 term to designate the fluids outside' of the capillaries but not in the lymph 

 vessels. They are divided into intercellular fluids and intracellular fluids. 

 Lymph production is a general term for the process involved in the pro- 

 duction of lymph, including fluid exchange, that is to say, exchange of 

 fluid, with its dissolved and suspended substances, in both directions be- 

 tween the capillaries and tissues. Edema indicates a pathological increase 

 in intercellular fluids. 



Disturbances in the Flow of Lymph. In man localized edema fre- 

 quently follows injury or blocking of the lymph channels. A common 

 example is elephantiasis, in which there is blocking of the lymphatics of 

 an extremity by parasites, such as Filaria. The role of alterations in the 

 lymph flow in the production of generalized edema, however, is not known. 

 Cohnheim, and also Klemensiewicz, believed that any increase in the 

 transudation of fluid from the capillaries is followed by an increase in 

 the lymph flow, but that edema occurs in spite of this, because the 

 lymphatics are unable to care for more than a certain amount of fluid. 



If this assumption were true, one should expect to find the superficial 



