CHEMICAL PHYSIOLOGY. 7 



the concentration of the gastric juice/it certainly, under 

 ordinary circumstances, does not transform the whole 

 of the starch into sugar. The gastric juice has no in- 

 fluence on starch; the pancreatic juice a trifling influence 

 in the same sense as saliva. Deducting all sugar and 

 lactic acid to be met with, it is necessary to assume 

 that other products are formed, which yet elude 

 analysis. Do any of these products find their way into 

 the liver, and are these transformed into glycogen ? 



G-lycogenis a kind of dextrine, which was discovered Sf nof 

 in the liver by Bernard and Hensen. It occurs in three 

 forms, of which one of the formula C 6 H 10 5 , is powdery, 

 two others, C 6 H 12 6 , and C 6 H 14 7 , are gummy. It 

 polarises to the right four times more intensely than 

 dextrose sugar. "With a solution of iodine in iodide it 

 gives a dark red colour. It dissolves copper oxyde 

 without reducing it. By sulphuric and hydrochloric 

 acids, saliva, pancreas juice, serum of blood, and cold 

 prepared extract of liver, it is transformed into dextrine 

 and ultimately into sugar. Many physiologists have 

 endeavoured to explain the source and destination of 

 this matter, but as yet without any very complete 

 success. Regarding its origin, it has been found that 

 it could not be formed from sugar, as the portal blood 

 did not contain any. It was not formed from fats. 

 Animal food enabled animals to form it, whence the 

 conclusion was drawn that glycogen originated in 

 albumen. Seeing that the liver decomposes albumen, 

 as proved by the constitution of the bile, this idea has 

 much in its favour, but the experiments upon which it 

 is based admit of different interpretation. Muscle 



