10 INTERNAL SECRETION 



experimentally by establishing a communication by means of 

 Eck's fistula between the portal vein and the vena cava of dogs, 

 thus enabling the blood from the portal vein to pass directly into 

 the general circulation without traversing the liver. After a few 

 days such animals show symptoms of acute poisoning; there are 

 changes in the sensorium, intervals of excitement and depression, 

 clonic and tonic spasms, and coma. These are sometimes spon- 

 taneous, but they are more likely to appear if the animals are 

 fed on meat. A similar picture of intoxication can be produced 

 in healthy dogs by the subcutaneous injection of carbamates. 

 When given by the mouth, there is no reaction to these salts 

 in normal animals ; those with Eck's fistula present the same 

 symptoms as after feeding with meat. The amount of ammonia 

 in the urine is increased, while the amount of urea is proportionally 

 diminished. 



These experiments show that, by the formation of urea, the 

 liver exercises a neutralizing activity, whereby the organism is 

 safeguarded from poisoning by ammonia. 



Up to the present, however, this is the only case in which we 

 are in a position to point with certainty, not only to the exact 

 nature of the poison but also to the organ which neutralizes it, 

 and, though this is only partial, to the chemical process by which 

 the transformation takes place. 



In most cases suspension of function, in man or animals, 

 gives rise to symptoms resembling those of auto-intoxication. It 

 must not be forgotten, however, that an assumption of auto- 

 intoxication founded upon the symptom-complex, has no real 

 explanatory value as long as we are without definite information 

 as to the nature of the toxic agent. Formerly, while the doctrine 

 of internal secretion was still in its infancy, the antitoxic action 

 of the organs was all too frequently invoked to explain the 

 symptoms which appear upon the suppression of any organic 

 function. But the fruitlessness of the search for the supposed 

 poison has led to a considerable modification of this hypothesis. 

 Indeed, the theory necessarily falls to the ground if we are able 

 to find another satisfactory explanation of the symptoms which 

 follow suppression. 



As a matter of fact, we have ample foundation upon which 

 to formulate another hypothesis. In every organ there is a store 

 of potential energy, a reserve of labour laid by in a special manner, 

 enabling it, upon adequate provocation, to fulfil its specific 

 function. Under normal conditions the potential energy is kept 

 in check and prevented from manifesting itself. The sight of an 

 organism showing signs of extreme suffering, racked with pain, 

 and with all the organs in a state of excessive activity, would 

 suggest, even to the untutored intelligence, that the potential 

 energy is relieved from its normal check, and that the bonds 

 are burst which had hindered the individual parts from the full 



