AN EXPERIMENTAL ANALYSIS OF OEDEMA 21 



cretion by the kidneys. If such a condition could be brought 

 about, it is plain that in course of time water would accumu- 

 late in the body in excess of normal. 



Experiments of this character made by the writer have 

 shown that when normal frogs are transferred from water 

 at room temperature to water at 36° C, such frogs, after 

 remaining in water at this higher temperature for about 

 thirty minutes, almost invariably show a slight loss in body 

 weight. As a matter of fact, it has been observed by the 

 writer that, within limits of temperature ordinarily consistent 

 with their natural environment, frogs at first usually lose 

 weight when taken from water at a low temperature to water 

 at a higher temperature, and gain weight when taken from 

 water at a high to water at a lower temperature. In the 

 average normal frog the power of the kidneys to maintain 

 at 36° C. a normal balance between the incoming and outgoing 

 flow of water signifies in the kidneys not only increased ac- 

 tion, but also a reserved functional capacity to meet quite 

 unusual conditions. While the behavior necessarily differs 

 in different cases, 36° C. is about the average limit at which, 

 in a normal frog, a normal balance can be maintained be- 

 tween the incoming and outgoing flow of water, provided, 

 however, the duration of the experiment is not too extended. 



If we may regard 36° C. as about the average limit of tem- 

 perature at which the kidneys can maintain a normal bal- 

 ance between the incoming and outgoing flow of water, what 

 conditions are met with when frogs are placed in water at 

 still higher temperatures! While it has thus far proved 

 impossible to determine for all cases the exact limits of tem- 

 perature at which the kidneys cease to meet the normal re- 

 quirements of excreting water, it has nevertheless been pos- 

 sible to demonstrate that when frogs are placed in water 

 at a temperature somewhere between 36° and 39° C, a slight 

 gain in body weight immediately follows. And, furthermore, 

 this gain in weight, slight though it may be, is within a short 

 time invariably accompanied by coma and cardiac inefficiency. 

 The result is that the rate of flow in the vascular channels is 



