188 COETEX 



shift of salt and water, to any change threatening its deviation 

 from the normal. To speak of an abeyance of the osmotic 

 forces, as assumed by some authors in discussing adrenal in- 

 sufficiency, is obviously as absurd as it would be to speak of an 

 abeyance of the law of gravity in explaining some terrestial 

 phenomenon. 



Gradinescu 236 first demonstrated that the osmotic pressure 

 of the blood was normal in adrenal insufficiency. Howard and 

 the author have also found that blood removed from dogs dying 

 from adrenal insufficiency has a normal freezing point thus 

 indicating that despite the profound changes occurring in the 

 composition of the blood, this physico-chemical property 

 remains constant. 



Stewart and Rogoff 588 found a decrease in the conductivity 

 of the blood and serum which would indicate an absolute 

 decrease in the total ionic concentrations. This decrease in 

 the concentration of the ionic constituents of the blood is com- 

 pensated for by the elevated non-protein-nitrogen of the blood 

 in maintaining the osmotic pressure at its normal value. 



We can picture the chain of events which bring about the 

 changes in the composition of the blood and tissues in adrenal 

 insufficiency as consisting essentially of the following events: 

 Renal injury causes in the early stages of insufficiency an 

 abnormal loss of sodium chloride, water, and certain other 

 threshold substances. This loss reduces the blood volume 

 which imperils the efficiency of the circulation. To overcome 

 this loss of blood volume, there is a passage of water from the 

 tissues into the blood stream, accompanied by a passage of 

 salts, to maintain a constant osmotic pressure. 



The changes in the inorganic constituents of the blood plasma 

 observed in adrenal insufficiency are reflected in corresponding 

 changes in the whole blood so that there is a shift of these elec- 

 trolytes between plasma and corpuscles to maintain the normal 

 equilibria existing across the corpuscular membrane. 



Attempts have recently been made to simulate the loss of 



