ON MEDICINAL PEPSIN. 
695 
digestion, and requiring for my purpose considerable quan- 
tities of medicinal pepsin, possessing the highest digestive 
energy, I purchased, in March last, samples of the principal 
English makers ; also some of a French, as well as one of a 
German maker. These were examined in the manner here- 
after described; and as the results arrived at corroborate 
substantially those obtained by Dr. Pavy seven years ago, 
although the methods of investigation adopted by that gentle- 
man and myself differ,* I beg permission to lay the following 
account of them before the readers of The Lancet, in the 
hope that it may induce those who are in doubt as to the 
value of pepsin as a therapeutic agent to reinvestigate the 
medicinal action of an agent which, according to theory, 
ought to render good service in cases in which the secretion 
of gastric juice is either deficient in quantity or defective in 
quality. 
Ten samples of pepsin, obtained from different sources, 
were examined. The preparations of the several makers are 
distinguished from one another by letters in the following 
manner : — 
A 1 
^ j>Same make, but purchased at different houses. 
Fresh eggs were kept in boiling water for an hour, and 
then allowed to get quite cold. After depriving them of their 
shell, the whites are cut into the thinnest possible slices, t and 
great care was taken to reject any portions of yelk, as well as 
all slices of white of ununiform thickness. A weighed portion 
of coagulated albumen thus prepared was placed in a two- 
ounce wide-mouthed bottle, and covered with distilled water 
containing one per cent, by volume of concentrated hydro- 
chloric acid.J These operations were conducted during the 
# Dr. Pavy noticed the relative solvent action on frogs’ legs of mixtures 
of pepsin and dilute acid. 
f It is easier to observe the progress of the digestion of albumen if it be 
sliced than if it be minced. 
| This degree of dilution was adopted from the circumstance that the 
D 
E 
F. 
ditto 
ditto, 
EXPERIMENTS UPON ALBUMEN 
