146 



Dr. F. W. Pavy. 



[Apr. 12, 



Modern research has shown that, besides the well-known carbo- 

 hydrate principles such as sugar, &c, there are several dextrins 

 distinguishable by their optical properties and their cupric oxide 

 reducing power. 



From the colloidal principle starch, which has no cupric oxide 

 reducing power, principles (dextrins) are producible by the action of 

 ferments possessing gradually increasing cupric oxide reducing power 

 until maltose is reached, which constitutes the final product, arid 

 which possess a little more than half the cupric oxide reducing power 

 of glucose. 



This is one foundation point connected with the researches I have 

 been conducting upon the physiology of the carbohydrates in the 

 animal system. 



The other foundation point is that the various members of the carbo- 

 hydrate group are brought into glucose by the agency of sulphuric 

 acid and heat. 



Proceeding upon these facts, and taking the cupric oxide reducing 

 power before and after subjection to the converting action of sulphuric 

 acid and heat, I have prosecuted investigations upon the transfor- 

 mation of the carbohydrates within the animal system with the 

 result of acquiring knowledge of an altogether unexpected nature. 



Hitherto what has been observed as regards the transformation of 

 carbohydrates by the action of ferments and chemical agents, has 

 been a change attended with increased hydration — for example, the 

 passage of starch into the successive forms of dextrin and maltose 

 and cane-sugar into glucose. 



The issue of the researches, however, which I have been con- 

 ducting recently is to demonstrate the passage of carbohydrates 

 exactly in the opposite direction by the action of certain ferments 

 existing within the animal system. 



Alike in the alimentary canal, the circulatory system and the liver, 

 the conditions exist by which this kind of transformation is effected. 



From the mucous membrane of the alimentary canal a ferment is 

 obtainable which converts (1) gin cose into a body possessing the 

 same kind of cupric oxide reducing power as maltose ; (2) cane- 

 sugar into maltose, and not glucose as formerly asserted ; and (3) 

 starch either into maltose or a dextrin of low cupric oxide reducing 

 power. 



The presence of carbonate of soda modifies the action of a maltose- 

 forming ferment, and leads to starch passing into a dextrin of low 

 cupric oxide reducing power instead of into maltose. 



The portal blood contains a ferment which possesses a maltose or 

 a dextrin-producing power, and the contents of the portal system 

 during digestion are charged with a notable amount of maltose some- 

 times, and at other times a low cupric oxide reducing dextrin. 



