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CHEMISTRY: K. G. FALK 
Presence of These Lipases in Other Materials. Soy beans were found 
to contain no esterase, but to contain a lipase having an appreciable 
solubility in water, but showing again a maximum solubility in a 1.5 
normal solution of sodium chloride. Both esterase and lipase were found 
to be present in human intestinal secretions obtained by means of duo- 
denal tubes. The esterase predominated in the secretions when no food 
had been taken for some time previously; and it is therefore probably 
present in the intestinal juice (succus entericus). The lipase predomi- 
nated after the ingestion of food; and it therefore doubtless occurs in 
the pancreatic juice and bile. 
Effect of Neutral Salts on the Rate of Hydrolysis of Esters by Enzymes. 
The effect of a number of neutral salts on the rate of the hydrolytic ac- 
tions produced by these enzymes was studied systematically over wide 
ranges of concentration. Similar results were obtained with the enzymes 
from different sources. In some cases the added salts showed very marked 
differences in their effect on the hydrolytic actions of the tvvo enzymes 
on their respective esters. The esterase action, for instance, was retarded 
by the presence of sodium chloride or sodium bromide, the retardation 
being distinct even at a concentration of 0.005 normal and increasing 
with increasing concentration of the salts. The lipase action, on the 
other hand, was increased by these salts up to a concentration of 0.1-0.2 
normal, and was then decreased, this decrease becoming considerable 
at high concentrations. Sodium fluoride produced a very strong retarda- 
tion with both enzymes even in solutions as dilute as 0.1 normal or less. 
The retarding action of sodium iodide was intermediate between that 
of the chloride or bromide and the fluoride. Other imi-univalent salts 
and certain uni-bivalent and bi-bivalent salts were studied similar^. 
Some of the bivalent radicals or ions, for example sulphate, were found 
to increase the lipolytic actions. 
The possibility that a deleterious action is exercised on digestive proc- 
esses by bromide and iodide when administered therapeutically in large 
amounts or over long periods of time was indicated by these results. 
The inhibiting actions of these salts were shown to be due to the fact 
that they precipitate or coagulate the enzyme-material. The coagula- 
tions were to some extent reversible at first, but long contact with the 
salt rendered them irreversible. 
Effect of Manganese Salts as Oxygen Carriers. Of all the salts studied 
manganous sulphate produced the greatest accelerating action with cas- 
tor and soy beans. In all probability this increased action is due to a 
large extent to the effect of the manganese as an 'oxygen carrier' in 
