144 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [August 20, I870-* 
medical men continue to prescribe, botli the good and 
the bad qualities of pepsin. Only a few days ago an old- 
established and well-known wholesale druggist told me 
that a customer applied to him for two ounces of pepsin. 
He asked the customer whose make he required. The 
reply was, “the cheapest.” On examining the kind of 
pepsin supplied on this occasion, it was found to be 
absolutely worthless as regards its power of digestion. 
Nevertheless it will be used medicinally and if the 
patient derives no apparent benefit from its administra¬ 
tion, the practitioner who prescribed it may be induced 
to condemn pepsin in toto ; or, should the patient soon 
get better, the improvement wall in all likelihood be 
attributed to a preparation which is perfectly inert. In 
the. first case, injustice w r ould be done to a medicine 
which is said by many eminent practitioners to possess 
great therapeutic value w r hen properly prepared; while 
in the second case, a worthless preparation would receive 
credit for performing a service it is totally incapable of 
rendering. 
. Being about to conduct some investigations on artifi¬ 
cial digestion and requiring for my purpose considerable 
quantities of medicinal pepsin, possessing the highest di¬ 
gestive energy, I purchased, in March last, samples of the 
principal English makers; also some French samples, 
and one of a German maker. These were examined in 
the manner hereafter described. The results arrived 
at corroborate substantially those obtained by Dr. Pavy 
seven years ago, although the methods of investigation 
adopted by that gentleman and myself differ.* The fol¬ 
lowing account of them may induce those who are in doubt 
as to the value of pepsin as a therapeutic agent to reinves¬ 
tigate the medicinal action of an agent which, according 
to theory, ought to render good service in cases wdiere 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 fol¬ 
lowing manner:— 
A ) 
I Same make, but purchased at different houses. 
33 ) 
| Ditto, ditto. 
C ) 
Cl > Ditto, ditto. 
C2 j 
D 
E 
F. 
EXPERIMENTS UPON ALBUMEN. 
Fresh eggs were kept in boiling water for an hour and 
then allowed to get quite cold. After depriving them of 
their shells, the whites were cut into the thinnest possi¬ 
ble slices,! great care being taken to reject any por¬ 
tions of yelk, as well as all slices of white of unequal 
thickness. A weighed portion of coagulated albumen 
thus prepared was placed in a two-ounce wide-mouthed 
bottle, covered with distilled water containing 1 per 
cent, by volume of concentrated hydrochloric acid.J 
These operations were conducted during the latter part 
of the day. Next morning the required amount of pepsin 
was weighed out and added to the mixture of albumen 
and dilute hydrochloric acid. The bottle and its con¬ 
* Dr. Pavy noticed the relative solvent action on frogs’ legs 
of mixtures of pepsin and dilute acid. 
t It is easier to observe the progress of the digestion of 
albumen if it be sliced than if it be minced. 
J This degree of dilution was adopted from the circumstance 
that the results of special experiments indicated that it was 
more favourable to digestion than an acid of greater or less 
strength. It was also ascertained that water containing five 
per cent, of hydrochloric acid appeared to prevent completely 
the digestive process taking place. Is it, therefore, wise to 
administer acids along with or immediately after pepsin, in 
cases in where the stomach already contains an excessive 
quantity of acid ? 
tents were then placed in a water bath and kept at a 
temperature of 38° C. (100-4° F.). Digestion was regarded 
as complete when, at the end of four hours, particles of 
albumen could no longer be seen, and when the insoluble 
residue consisted of a very minute quantity of fibrous or 
membranous matters only. These observations were 
easily made, except in the experiments upon samples of' 
pepsin containing large quantities of starch. In such 
cases, when digestion appeared to be finished, the result 
was not recorded until the contents of the bottle had 
been carefully elutriated, or strained through fine muslin, 
so that it might be ascertained with certainty, by the 
appearance of the residue in the bottle or on the filter 
(muslin), whether or not the whole of the albumen had 
been dissolved. 
In the first series of experiments upon albumen, 5- 
grammes of coagulated egg-albumen and 25 cubic centi¬ 
metres of distilled water, containing 1 per cent, of hy¬ 
drochloric acid, were employed. The quantities of pep¬ 
sin used are stated in the subjoined table, which is in¬ 
tended to show the relative amounts of the different 
makers (A, B, C, D, E, F) required to digest the same 
quantity of albumen in four hours. Two comparative- 
experiments were in every instance set going at the same¬ 
time. 
Table showing 'Results of First Series of Experiments on 
Albumen (25 cubic centimetres of acidulated water). 
Weight of 
Pepsin 
employed. 
MAKE OF PEPSIN. 
A. 
B. 
C. 
D. 
E. 
F. 
Grammes. 
0*050 { 
0-075 
o-ioo 
0-150 
0-175 
0-200 
0-250 
0-300 
i 0-400 
! 0-500 
1-000 
1- 500 
2- 000 
3- 000 
4- 000 
5- 000 
Digested. 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
digested 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto* 
■M • 
• • • 
4«« 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
It having been found impossible to continue the ex¬ 
periments on make C, with more than 1*5 gramme of 
pepsin, in consequence of the inability of 25 cubic cen¬ 
timetres of acidulated water to keep the mixture in a 
sufficiently liquid state, a second series of experiments 
were commenced, in which 50 instead of 25 cubic centi¬ 
metres of diluted acid was employed. The weight of albu¬ 
men used was the same as that in the first series, viz. 5 
grammes. 
Table showing Results of Second Series of Experiments upon 
Albumen (50 cubic centimetres of acidulated water). 
Weight of 
Pepsin 
employed. 
MAKE OF PEPSIN. 
A. 
B. 
C. 
D. 
E. 
F. 
Grammes. 
0-050 { 
0-250 
0-300 
0-400 
0-500 
1-000 
1-250 
5-000 
Digested. 
Not 
digested 
ditto 
ditto 
ditto 
digested 
• • • 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
digested 
• M 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
* Experiments with this make of pepsin were here discon¬ 
tinued, in consequence of the 25 grammes of acidulated water 
employed being insufficient to maintain the requisite fluidity 
of the mixture. 
