568 SCIENCE PROGRESS 



The essential influence exercised by the pancreas on the 

 carbohydrate metabolism of the body was demonstrated nearly 

 twenty years ago by von Mering and Minkowski, who described 

 the fatal diabetes which ensued on total extirpation of this organ. 

 Their experiments, with those of later observers, make it almost 

 certain that the pancreas yields some internal secretion to the 

 circulating fluids of the body, the presence of which is an 

 indispensable condition for the assimilation of sugar either 

 by the liver or the muscles. All attempts to imitate the action 

 of the living pancreas by means of extracts of the organ have 

 so far failed. If, however, this internal secretion is of the same 

 nature as the other bodies, which I have included under the 

 term "hormones," it should be possible to isolate, by some means 

 or other, the active principle from the gland and, by the intro- 

 duction of this substance into the blood-stream, to materially 

 influence for good those cases of diabetes in man, which are due 

 to pancreatic disease. 



The important part played by internal secretions in the 

 regulation of the activities of the entire body has long been 

 realised by physiologists. The special point which I have 

 endeavoured to emphasise in this article is that these internal 

 secretions or hormones, as I have called them, are of a relatively 

 simple chemical character, that they are susceptible of isolation 

 and even, as in the case of adrenalin, of synthesis, and that their 

 action is not that of a foodstuff, but of a drug, depending, as it 

 does, on the chemico-physical configuration of the molecule, 

 and not on the presence of haptophore groups, which would 

 determine their assimilation into the living protoplasmic 

 molecule. These hormones are widespread in their distri- 

 bution and their effects, and we may hope that further investi- 

 gations along these lines will place in our hands an armament 

 of potent agents by which we may control many of the most 

 important functions of the body. 



