PRODUCTION OF SUGAR IN THE LIVER. 297 



than the liver and the blood coming from the liver. As the 

 blood from the liver is mixed in the vena cava with the blood 

 from the lower extremities, and in the right side of the heart, 

 with the blood from the descending cava, the amount of sugar 

 is proportionately diminished in passing from the liver to the 

 heart. It was found that the sugar generally disappeared in 

 the lungs, and did not exist in the blood of the arterial sys- 

 tem. Assuming that these statements have been sustained 

 by experimental facts, there can be no doubt that the liver 

 produces or secretes sugar ; that this secretion is taken up 

 by the blood ; and that the sugar is destroyed in its passage 

 through the lungs. 



The question of the production of sugar in the economy 

 has given rise to a great deal of discussion, and the experi- 

 ments of Bernard have been repeated very extensively. 

 Many physiologists of high authority have been able to 

 verify these observations in every particular; but others 

 have published accounts of experiments which seem to dis- 

 prove the whole theory. 



There can be no doubt of the fact that sugar may, under 

 certain conditions, be produced de novo in the organism. 

 Cases of diabetes, in which the discharge of sugar by the 

 urine continues, to a certain extent, when no starch or sugar 

 is taken as food, are conclusive evidence of this- proposition. 

 It is a fact equally well established, that the sugar taken as 

 food and resulting from the digestion of starch is consumed 

 in the organism, and is never discharged. The fact with re- 

 gard to diabetes shows, then, that it is not impossible, when 

 no sugar or starch is taken as food, that sugar should be pro- 

 duced in the body ; and the failure to find the sugar of the 

 food in the blood or excreta shows that this principle is nor- 

 mally destroyed or consumed in the organism. It only re- 

 mains, therefore, to determine whether the production of 

 sugar in diabetes be a new pathological process, or merely 

 the exaggeration of a physiological function. 



We have so often repeated and verified the observations 



