352 DIGESTION. 



taken as food is digested in the' small intestine. Though the 

 intestinal juice is capable of effecting its transformation into 

 sugar, the experimental evidence is conclusive that in this 

 it is subordinate to the pancreatic juice, which latter effects 

 this transformation, at the temperature of the body, with 

 extraordinary activity. There is no evidence that the bile 

 has any thing to do with this action ; and, indeed, it is stated 

 by Lehmann, that starch is not materially affected by the 

 bile, even after prolonged digestion. 1 



To sum up the whole process of the digestion of starch, 

 it may be stated, in general terms, that this principle, when 

 hydrated, which is the usual condition in w^hich it is taken 

 into the stomach of the human subject, is slightly acted upon 

 by the saliva, both in the mouth and after it has passed into 

 the stomach when it is taken raw, it is hydrated in the stom- 

 ach, and usually undergoes no transformation into sugar until 

 it has passed into the small intestine ; and when it passes out 

 at the pylorus, mainly by the action of the pancreatic juice 

 but with the assistance of the intestinal juice, it is trans- 

 formed into glucose, and in this form is absorbed. 



We have already followed out the digestion of sugar as 

 far as the small intestine. 2 Glucose undergoes no change in 

 the stomach, and is taken directly into the circulation. It is 

 probable, also, from the experiments of Bouchardat and 

 Sandras and others, that a small quantity of cane-sugar may 

 in like manner be taken up by the blood-vessels of the in- 

 testinal mucous membrane. 3 It has been shown that a small 

 quantity of cane-sugar is transformed into glucose in the 

 stomach, but, as we noted in treating of stomach-digestion, 

 the quantity is inconsiderable, and the transformation de- 

 pends simply upon the presence of a free acid in the gastric 

 juice. 



1 LEHMANN, Physiological Chemistry, Philadelphia, 1855, vol. i., p. 492. 



2 See page 268. 



3 BOUCHARDAT ET SANDRAS, De la Digestion des Matieres Feculentcs et Sucrees, 

 etc. Supplement d TAnnuaire de Therapeutigue, Paris, 1846, p. 81 et seq. 



