iQii] Jacob Rosenbloom 277 



ventricle, thus hindering its action and producing a disproportion 

 between the action of the right and left ventricles. 



Mayer soon made similar experiments with the same results. 

 He thought that this type of edema is due to an obstruction to the 

 return of blood from the lungs and by the driving of blood into 

 the organ by accessory f orces such as ( i ) increased tone of the 

 vessel wall, (2) increased pumping force of the thorax, and (3) 

 spasm of muscle, especially the diaphragm and abdominal muscles. 

 Colin (1883) repeated the work with the same results and found 

 that the vasomotor nerves played an unimportant part, while 

 Ranvier (1869) held that vasomotor paralysis was a necessary 

 factor. 



Landerer (1884) claimed that alterations in the elasticity of the 

 tissues is the primary factor in the change of the circulation of the 

 blood and lymph, and that edema is the result of an impairment 

 of the elastic equilibrium of the circulating fluids of the body. 



Salvioli (1885) confirmed all of Cohnheim's results but sug- 

 gested no other influence than filtration in the production of edema. 

 He thought that transudation was dependent upon the nutrition of 

 the animal, the concentration of the injected fluid, and the pressure. 

 The principal cause of edema in Salvioli's view is the permeability 

 of the vessel walls, which he tried to explain upon a purely mechan- 

 ical basis. 



Von Basch considered that edema of the lung was caused by 

 the rigidity of the walls of the alveoli as induced by pulmonary 

 hyperemia, the diminished elasticity of the tissue giving rise to 

 edema. 



Sahli (1884) denied that edema of the lungs is due to an ob- 

 struction. He believed that impaired action of the left auricle or 

 spasm of heart muscle can never cause the increase of blood pressure 

 in the circulation of the lungs which is necessary for the production 

 of edema. He considered that edema was due to local altera- 

 tion of the capillary walls. 



Dickenson (1893) investigated the question whether filtration 

 or diffusion played the principal röle in edema. He concluded 

 that diffusion is the principal factor in the interchange of salts, 

 while blood pressure determines the escape of albuminous con- 



