DR. PAVY AND DIABETES 15 



years earlier, this great physiologist had published his account 

 of the experiments which established belief in what is gener- 

 ally known as the glycogenic function of the liver ; Pavy, 

 during his visit, doubtless received an account of the work at 

 first hand. 



It is well to be clear with regard to the exact use of the 

 expression " glycogenic " as at first applied to the functions of 

 the liver. Bernard had set himself to explore the organs of the 

 body in the endeavour to locate the regions in which sugar is 

 utilised and destroyed. His hope was to discover what deficiency 

 might be responsible for the condition of diabetes and by 

 mitigating that deficiency to effect a cure of the disease. He 

 already knew that all carbohydrate food leaves the intestine in 

 the form of dextrose. The liver is an organ standing in the 

 path of transference from the intestine to the tissues and Bernard 

 first sought evidence for the destruction of the dextrose in that 

 organ. He found, however, that sugar was present in the 

 blood of the hepatic veins immediately beyond the liver during 

 the absorption of carbohydrate from the intestine. He then dis- 

 covered something more striking : that when the animal was 

 not taking carbohydrate but consuming flesh alone — no sugar, 

 therefore, flowing from gut to liver — sugar was still to be found 

 leaving the latter continuously and passing into the general 

 circulation beyond it. Claude Bernard held, therefore, that 

 sugar must be actually made in the liver. 



All this was before he had discovered the nature of the 

 actual precursor of the sugar which leaves the liver and he 

 conceived at this time that the organ elaborated carbohydrate 

 from material which was not carbohydrate ; actually it " secreted " 

 sugar and was in a literal sense of the word "glycogenic." 

 Later, however, Bernard discovered that the precursor — at all 

 events, the main precursor — of hepatic sugar was itself a carbo- 

 hydrate, a polymerised sugar, in fact, which easily gave rise to 

 sugar under simple treatment. Its discoverer recognised the 

 physiological analogy of this substance with another complex 

 carbohydrate — the starch of plants— and though now known as 

 glycogen it has often been called " animal starch." The term 

 11 glycogenic," as applied to the liver, now took on a somewhat 

 different aspect ; the organ is not in the main concerned in the 

 production of carbohydrate de novo but is a particularly 

 capacious storehouse of carbohydrate awaiting utilisation. Its 



