and Toxic Agents on the Amylolytic Action of Saliva, 
~T 
~vT 
Influence of gases on the amylolytic action of saliva. 
The well known analysis by Pfliiger* of the gases of the submax- 
illary saliva have shown the presence of both oxygen and carbonic 
acid in this secretion; oxygen to the extent of 0°6 vol.-per cent. and 
carbonic acid, by pump extraction, 22°5 vol.-per cent. It is, moreover, 
a well known fact that as the saliva flows into the mouth and 
becomes mixed with the food during mastication much air is ab- 
sorbed. Do these three gases exert any influence on the amylolytic 
action of the ferment with which they are so constantly in contact ? 
Again, the amylolytic ferment of the pancreatic secretion, so near 
yakin, it not identical with the salivary ferment, is subjected to the 
influence of the reducing gases of the intestinal canal, among which 
hydrogen may be present to the extent of 220+ vol.-per cent. and 
hydrogen sulphide in traces. What likewise is the effect of these 
two gases on amylolytic action ? 
The experiments were conducted as follows: 90 ¢. c. of diluted 
starch paste were placed in small, partially stoppered flasks and a 
stream of the gas allowed to pass through, until the fluid was thought 
to be saturated, then 10 c.¢. of dilute saliva were added and the gas 
allowed to bubble through the solution for 30 minutes when the 
mixtures were boiled and the reducing bodies determined. Follow- 
ing are the results: 
Total amount Starch. 
Gases. Wt. Cuin 4. reducing bodies. converted. 
0 071319 gram. 0 2684 gram. 24°15 per cent. 
ATP CR Stee eu svdde Shs 0°13€5 0°2780 25:02 
Oxyorenetss5%. ceckos = 071511 0°3080 20-72 
Carbonic acid...-.--.- 0°1537 0°3136 28°22 
Hydrogen sulphide ----0°1377 0°2804 — 25.23 
iEydropeniss2 2---+=: 0°1248 0°2540 22°86 
It is interesting to see that air, oxygen and carbonic acid all stimu- 
late and approximately in proportion to the extent in which they are 
present in the natural secretion, while of the sees gases hydro- 
gen retards and hydrogen sulphide stimulates. 
The following table shows the relative acceleration and retardation 
of the several gases, compared with the control, expressed as 100. 
AUT We Oe Wet Je ek ts ee ees 103°6 
Oxygenias2 85 2s ul Seer ee eee ss 114-7 
Carbonic /aeila=2 52.2.5 Serer a eo 116°8 
Hydrogen sulphide.) 2 2eosoe. - ee ce 104.4 
la OO RN oe RO eee ees Saeaee eee 94°6 
* Physiologische Chemie, Hoppe-Seyler, p. 192. 
+ Maly in Hermann's Handbuch der Physiologie, vol, v, p. 25, 
