1892-93.] Di: 'RobQictHOTi on the Digestion of Sugars. 31 
nearly the same that I think we may safely conclude that the saliva 
has no effect in hastening the inversion of cane sugar. 
I next sought to ascertain the influence of gastric juice on cane 
sugar. The juice contains from 0‘2 to 0'3 p.c. of free hydrochloric 
acid. To a 20 p.c. solution of cane sugar I added 0‘2 p.c. 
hydrochloric acid, and kept it at 38° C. At the end of one hour it 
contained 0*37 p.c. invert sugar. After two hours the amount rose 
to 0‘45 p.c. 
If we compare the amount of invert sugar formed in the presence 
of acid with that formed in its absence, we find that the acid nearly 
doubles the amount produced. Thus — 
Cane Sugar 20 p.c. Sol. at 38° C. 
Invert Sugar. 
In one hour. 
In two hours. 
(1) Alone 
(2) With 0*2 p.c. HCl 
0'19 p.c. 
0-37 „ 
0-252 p.c. 
0-45 ,, 
At the end of two hours only about ^^-g-th part of the cane sugar had 
undergone inversion in the presence of acid similar in amount to 
that of the gastric juice, and at the temperature of the stomach, 
I then examined the effect of normal gastric juice on cane sugar. 
With the aid of an oesophageal tube I washed out the stomach of a 
healthy man, and then injected about three ounces of dilute liquor 
carnis consisting of the extractives of flesh. One hour later I intro- 
duced the stomach-tube and drew off the gastric contents. I filtered 
this fluid and found that it contained 0T5 p.c. hydrochloric acid, 
and, as was to be expected, no sugar. 
I then made a mixture of equal parts of this healthy gastric fluid, 
distilled water, and 20 p.c. solution of cane sugar. The sugar in 
the mixture was thereby reduced to about 6 ’6 p.c., and the hydro- 
chloric acid to O'Oo p.c. After keeping it at the usual temperature for 
two hours, the invert sugar formed amounted to 0’83 p.c. 
I was so struck by the relatively large amount of invert sugar 
produced in a fluid containing only a third of the amount of cane 
sugar and a third of the amount of acid as was contained in the 
