August 20,1370.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
145 
From the results of the experiments detailed in the 
foregoing tables, it will he seen— 
1st. That, in order to effect the digestion of a given 
weight of albumen, very different quantities of the pepsin 
prepared by makers A, B, C are required. 
2nd. That, taking the digestive power of C as unity, 
the digestive ratios of A, B, and C are as follows:— 
C = 1 (1-25 gramme dissolves 5 grammes of albumen.) 
B=2‘5 (0-50 „ „ „ „ ) 
A=25 (0-05 „ # „ „ „ ) 
In other words, A is ten times as strong as B, and 
twenty-five times as strong as C. 
3rd. That, inasmuch as coagulated albumen mixed 
with acidulated water and equal weights of D, E, and F 
did not give the slightest indication of being digested, 
even at the expiration of twenty-four hours from the 
-commencement of the experiment, it is evident that such 
samples of pepsin are, to say the least, practically desti¬ 
tute of the power of digestion. A 1, B 1, C 1, and C 2 were 
tested in precisely the same manner as the other samples; 
it was found that their digestive powers did not ma¬ 
terially differ from the corresponding samples A, B, and 
C, which, it will be remembered, were prepared by the 
.same makers, but obtained from different sources. 
The evidence afforded by the results of the experi¬ 
ments already referred to, will doubtless be considered 
quite sufficient to prove the existence of a wide dif¬ 
ference in the digestive energy of certain samples of pepsin 
met with in pharmacy, and the utter worthlessness of 
others. Nevertheless, the following series of experiments 
upon fibrin was undertaken for the purpose of ascertain¬ 
ing whether or not the results would accord with those 
■obtained in the previous investigations upon albumen. 
EXPERIMENTS UPON FIBRIN. 
In these experiments 5 grammes of finely-minced fibrin 
(lean of rumpsteak) was mixed with 50 cubic centimetres 
of distilled water containing 1 per cent, by volume of 
concentrated hydrochloric acid, and the quantities of 
pepsin stated in the following table. Temp. 38° C. 
(100-4° F.); duration of experiment, four hours. Two 
■comparative experiments were invariably set going at 
the same time. When, in consequence of the presence 
■of starch, the progress of digestion could not be satisfac¬ 
torily watched, the mixture was strained through fine 
muslin for the purpose previously named when describ¬ 
ing the mode of experimenting with albumen. 
Table showing Results of Experiments upon Fibrin. 
Weight of 
Pepsin 
employed. 
MAKE OE PEPSIN. 
A. 
B. 
C. 
D. 
E. 
P. 
Grammes. 
0-45 { 
1-00 
1- 50 
2- 00 
3- 00 
4- 00 
5- 00 
Digested. 
Ml 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
• • • 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
Not 
digested 
ditto 
• ditto 
ditto 
ditto 
ditto 
ditto 
Not 
digested 
ditto 
ditto 
ditto 
ditto 
ditto 
ditto 
We are now enabled to see— 
1st. That the relative digestive power of A and B on 
■fibrin was very nearly the same as with albumen, the 
ratios being 
10 A to 1 B with albumen; 
8-88 (in round numbers 9) A to 1 B with fibrin. 
> 2nd. That inasmuch as 5 grammes of fibrin was un¬ 
digested by equal weights of pepsins C, D, E, and F, 
these preparations are practically destitute of medicinal 
■value.* 
Having shown, from the results of nearly three hun¬ 
* The fibrin remained undigested even at the end of 
twenty-four hours from the commencement of these experi¬ 
ments. 
dred experiments upon albumen and fibrin, that the pep¬ 
sin distinguished by the letter A is far superior in quality 
to that of any other make, it appears to me simply an 
act of duty to the medical profession and of justice to 
the undermentioned firm, to state that it is prepared by 
Messrs. Bullock and Reynolds, of Hanover Street, Han¬ 
over Square.* In conclusion, I beg to thank my very 
able assistant, Mr. E. Lapper, for the aid he has rendered 
me during the prosecution of this inquiry. 
HYDRATE OF CHLORAL. 
In one of a series of articles on the “ Progress of The¬ 
rapeutical Science,” tho ‘Medical Times and Gazette’ 
mentions that some years ago the late Sir J. Y. Simpson 
predictedf that among the organic compounds constantly 
being discovered by chemists some one would be found 
“ as important as that most useful of all drugs—opium— 
and yet without either its constipating effects, or in¬ 
direct tendency to excite subsequent nausea.” Such a 
substance was found before his death in hydrate of chlo¬ 
ral. From the same article we take the following par¬ 
ticulars :— 
Chloral itself was discovered by Liebig, in 1832; sub¬ 
sequently it was further examined by Dumas, but up to 
last year it remained a substance of merely chemical in¬ 
terest. Though itself a thin, colourless oil, clearer than 
water, greasy to the touch, possessing a peculiar pungent 
odour, and exciting a copious flow of tears, it forms 
with water a solid crystalline compound; and, as shown 
by Liebreich, of Berlin, this compound possesses great 
power as a hypnotic and ansesthetic. The hydrate of 
chloral contains 89*02 per cent, of chloral and 10-88 
water. It dissolves freely in water, a saturated solution 
containing about 50 per cent. When pure, its diluted 
solution has a rather agreeable taste, a point of no small 
importance in its favour. 
Dr. Richardson has characterized Liebreich’s discovery 
of the medicinal virtues of chloral hydrate as a brilliant 
illustration of modern advance in therapeutics, inasmuch 
as it was arrived at by a determination of the action of a 
substance theoretically from a precise knowledge of its 
chemical and physical properties. Hydrate of chloral re¬ 
acts with an alkali in such a manner that they are re¬ 
solved into chloroform and a formiate. The blood being 
an alkaline liquid, Liebreich inferred that it ought 
therefore to produce this change, and that if chloral 
hydrate were introduced into the animal organism, 
“ every small particle of it would consume the surround¬ 
ing alkali, the decomposition being completed only after 
the requisite quantity of alkali had been furnished by 
the blood within an infinitesimal period; a minimum 
quantity of chloroform would thus be formed and passed 
to its first place of action, viz. the ganglia cells of the 
cerebrum.” On account of the slight alkalinity of the 
blood, formation of chloroform would not take place ex¬ 
plosively, as it were, but gradually and slowly, its own 
peculiar action would therefore also be exercised gradually 
and slowly on the ganglia of the cord, and lastly on the 
heart. 
Liebreich first experimented with the substance on 
animals, and finding his anticipations realized, then ex¬ 
tended his observations to man. His results were com¬ 
municated to the Academy of Sciences in Paris during 
1869, and he has since published a valuable pamphlet on 
the properties of chloral hydrate.]; Last August, during 
the meeting of the British Association at Exeter, speci- 
* Dr. Pavy also showed in 1863 that the pepsin of Messrs. 
Bullock and Reynolds was much more active than that of any 
otlier mother* 
f ‘Physicians and Physic,’ 1856, p. 100; ‘Monthly Jour¬ 
nal of Medical Science,’ vol. xvi. p. 359. 
x ‘ Das Chloral Hydrat, ein neues Hypnoticum und Aniis- 
thesien,’ etc. Yon Dr. O. Liebreich. Berlin, 1869. 
