DIGESTIBILITY OF BEE ADS. 



69 



aud next, breads made with tartaric acid powder, lastly those other breads made from alum 

 and phophates powder, with a preference for the latter. (It is to be remembered that the 

 phosphate powder contained calcium sulphate — about 13 % — which is shewn later to 

 be a strong retarding agent.) (2) That the amylolytic ferment of the saliva is more influ- 

 enced by these salts than is that of the pancreas. 



In order (a) to estimate more accurately the products of digestion, (b) to determine, 

 if possible, which of the ferments was most influenced by the constituents of the baking 

 powders, and (c) which one of the constituents of bread was most affected, the experi- 

 ments detailed in the next division were tried. 



B. 



The Influence of Certain Baking Powders on the Digestion of 

 Fibrin, G-luten and Starch. 



The materials to be digested consisted of, (1) a 1 % solution of potato starch, made 

 neutral by washing with large excess of water ; (2) gluten obtained from gluten flour, 

 thoroughly washed, separated as completely as possible from starch and dried at 100 to 

 120° C ; (3) fibrin, separated from blood clot, washed with water, alcohol and ether, slowly 

 dried at 100' and reduced to powder. 



To each digestion mixture, made up to 50 c.c. was added 0.05 % of one of the 

 powders. This quantity corresponds approximately with the amount required by the 

 directions for the use of each powder. The ferment was added after the powder had been 

 thoroughly incorporated with the mixture. 



Table 1. — The Relatirc Influence of the three Poiedcrs on the Amijlohjilc Ferment of Saliva. 



Here, as in ]5revioiis experiments, 2 c. c. of filtered mixed saliva were taken, and the 

 mixture made up to 100 c.c. with 1 % starch solution. The digestion was stopped at the end 

 of thirty minutes and the reducing substances estimated as glucose by a standard Fehling's 

 of solution. in the table represents control experiment, composed of 100 c. e. of 1 % 

 starch and with 2 c. c. of saliva. 



In the following experiments 2 grammes of the material for digestion were taken 

 and 2 c.c. of glycerine extract of pepsin added to each mixture, which was made up to 

 50 c.c. by 0"2 % solution of hydrochloric acid. Time, 2 hours. Control experiment taken 

 at 100, the weight of the undigested fibrin and gluten was estimated as the measure of 

 the relative action of the ferment. 



