1895 - 96 .] Dr Aitchison Eobertson on Digestion of Starch. 103 
When neutralised and kept for three-quarters of an hour at 38° C., 
the sugar increased to 0'63 per cent. 
One hour after eating the starch, 100 c.c. of turbid fluid were 
obtained. 
The total acidity was equal to 0T75 per cent, as hydrochloric 
acid. 
Much starch remained; erythrodextrin was present and 0T53 
per cent, of sugar. 
After being neutralised and kept at 38° C. for forty-five 
minutes, the sugar remained almost identical in amount (0T54 
per cent.). 
Combined Digestion of Starch by Saliva and Gastric Juice. 
Healthy Digestion. 
Chronic Gastric Catarrh. 
Time in Minutes of \ 
Stay in Stomach, / 
15 
60 
15 
60 
10 
60 
No. of c.c. withdrawn, 
40 
45 
45 
38 
80 
100 
Total acidity as HC1, 
0-061 
0-102 
0-138 
0-196 
0-102 
0-175 
Starch, 
much 
much 
much 
little 
much 
much 
Erythrodextrin, 
much 
traces 
much 
none 
some 
some 
Sugar, per cent., 
0-16 
traces 
trace 
none 
0-4 
0-153 
After neutralisation. \ 
At 38°C. for 45 min. I 
no change 
no change 
no change 
no change 
0-63 
0-154 
From this we learn that even a short stay in the stomach during 
the digestion of a simple carbohydrate suffices to kill the ferment 
ptyalin. This ferment acts with great rapidity, and the amount of 
starch which was found in the stomach converted into dextrins 
and sugar had probably undergone this change during the process 
of mastication and swallowing, and for a short period after its 
entrance into the stomach. 
In the case of the dyspeptic, the ferment was not killed after 
a stay of ten minutes in the stomach, and was still able to continue 
its amylolytic action in a less acid medium. A stay of five 
minutes longer, however, in the stomach, during which time the 
amount of acid had increased, was enough to destroy the fer- 
ment, for, after being neutralised, no further amylolytic action 
took place. 
