August 17,1872.] 
THE PHARTilACEUTICAL JOURNAL AND TRANSACTIONS. 
123 
eight degrees—from 54° C. to 40° C.—and its lowest 
ten degrees—42° C. to 32° C.—the cerate, like the 
wax contained in it, having two melting-points 
which are separated by fourteen degrees. 
(2) White Beeswax and Olive Oil—At 39° C. it 
commences to lose a little of its opacity; from 42° C. 
to 52° C. it becomes more and more translucent; 
at 54° C. transparent; at 50° C. runs slowly; at 
57° C. it runs easily. So that a mixture of olive oil 
with beeswax in the proportions indicated, lowers 
the melting-point seven degrees. Just as there is 
a difference of ten degrees between one of the melt¬ 
ing points of Japanese wax and that of beeswax, 
there is a difference of ten degrees between those of 
the two cerates. 
The observation of the melting-point alone would 
not be sufficient to distinguish between cerate made 
from vegetable wax and that from beeswax, as the 
melting-point might depend upon the proportion of 
olive oil present. But the existence of only a single 
point of fusion in beeswax might be a useful indica¬ 
tion as to the presence or absence of Japanese wax, 
or probably of margarine or stearine. A cerate 
made with beeswax may also be distinguished from 
one made with Japanese wax by the action of a strong 
alcoholic solution of caustic potash, which dissolves 
entirely, even in the cold, a cerate made from the 
vegetable wax, but only dissolves very incompletely 
one made from beeswax. 
It will thus be seen that from a pharmaceu¬ 
tical point of view the effect of substituting Japanese 
for beeswax, in medicaments having wax for their 
base, is a notable lowering of their melting-point; 
and a cerate made of the proportions indicated above 
would melt at the temperature of the human body, 
the mean of its two melting points being about 37° 
C. or 38° C. It will, therefore, be evident that such 
a substitution should not be made without the 
greatest care .—Journal de Pharmacie et de Chimie, 
[4] vol. xvi. p. 20. 
ACTION OF PEPSIN ON THE FIBRIN OF BLOOD.* 
BY VOX WITTICH. 
A number of the experiments related in this paper 
were made by Griinhagen’s method, but as the time 
when the first drop falls from the filter is influenced by 
the thickness of the paper employed, etc., the author 
prefers to take the amount of filtrate in a given time as 
a measure of the activity of digestion. He determines 
the total amount of the products of digestion by the 
lmvo-rotation of polarized light in a Soleil-Ventzke’s 
apparatus, and the amount of peptones formed, by 
neutralizing the liquid so as to precipitate para-peptones, 
and again noting its rotatory power. He assumes 
that one division of the scale represents 1 per cent, of 
peptones, or other albuminous substances in solution, 
with sufficient exactness for comparative experiments. 
In preparing a glycerin solution of pepsin from the 
mucous membrane of a stomach, he recommends that 
the pyloric part should be rejected entirely, as the 
mucus" it contains hinders the filtration of the glycerin 
extract ; and he finds, in accordance with Friedinger 
and Fick, but in opposition to Haidcnhain and Ebstein, 
that it contains little pepsin. He now finds that pepsin 
may be extracted from gastric mucous membrane after 
it has been steeped in alcohol, or from the precipitate 
which is produced in glycerin extract of fresh mucous 
* (Piliigers Archiv. fur Physiologic, v. 435-469). 
membrane by the addition of alcohol. The glycerin 
must, however, be allowed to remain in contact with 
the mucous membrane or precipitate for several days, 
and the negative results which the author formerly ob¬ 
tained were due to his having tested the peptic proper¬ 
ties of the glycerin after 24 hours instead of after 
several days. He is not certain whether pepsin is 
albuminous or not, for though it does not give the 
reactions of albumen, this might be due to the exces¬ 
sively small quantity of it present. It differs from 
albuminous substances in resisting putrefaction ; it 
agrees with them in being almost entirely indiffusible 
into distilled water. It diffuses, however, very rapidly 
into dilute hydrochloric acid of 2 per thousand. He 
thinks this is due to the formation of a diffusible com¬ 
pound with the acid. Fibrin absorbs pepsin most ener¬ 
getically. When put into water into which pepsin can 
dialyse, it causes it to pass through the parchment more 
quickly. An excess of fibrin will absorb from artificial 
gastric juice all the pepsin which has already digested a 
part of it, and when the undissolved fibrin is taken out 
and put into fresh acid, the pepsin it contains is gene¬ 
rally sufficient to dissolve both it and additional fibrin 
added to it, while the liquid from which it has been 
removed has lost all peptic properties. When, how¬ 
ever, fibrin is digested upon a filter, the pepsin runs 
from the filter together with the products of digestion, 
so that the amount of pepsin remaining with the fibrin 
on the filter gradually diminishes,. and its digestion 
consequently becomes slower. This circumstance, as 
well as the fact that the pepsin becomes diffusible in 
presence of free acid, causes him to believe that the 
process of digestion begins by pepsin forming a loose 
chemical compound with the acid, and that this com¬ 
pound is the active agent in the process. He considers 
that they combine in definite proportions. Deficiency 
of acid will stop digestion although pepsin be present. 
When fibrin is digested with pepsin, not on a filter 
but in a glass, so that they remain in contact during the 
whole time of digestion, the amount of fibrin digested is 
in proportion to the amount of pepsin added. . The 
rapidity with which digestion begins is dependent in the 
first place on the amount of pepsin. The rapidity with 
which digestion is performed increases with the tem¬ 
perature up to about 50° C. It goes on, though \ ery 
slowly, even at such a low temperature as o C., attains 
its maximum rapidly between 35° and 50 , and aboA e 
this becomes slower. Schiff’s statement that the activity 
of pepsin is suspended at temperatures under 13 is in¬ 
accurate. Exposure to 5° for some hours does not destroy 
the activity of pepsin. The activity of a dilute solution 
of pepsin is destroyed by exposure for two minutes to 
70°, while that of an undiluted glycerin solution was re¬ 
tained after exposure for the same time to 80°. 
When digestion stops before all the fibrin in a diges¬ 
tive solution has been dissolved, the arrest of the piocos.> 
’is not due entirety to the accumulation of products of 
dffiestion, as the amount of those at the time of arrest is 
found to vary considerably, but is partly due to the w ant 
of free acid. His explanation of this is that a definite 
amount of pepsin and of acid is requisite lor the diges¬ 
tion of a given quantity of fibrin.. The .fibrin which 
remains undissolved in an otherwise active digestive 
fluid, has part of the acid which it has absorbed with¬ 
drawn from it during the process of digestion, so that 
the quantity" it retains is too small for its digestion, al¬ 
though it has absorbed all the pepsin which has finished 
digesting the rest of the fibrin. The presence of water 
is necessary to digestion, and an insufficient quantity of 
it retards the action of pepsin. # , . 
The proportion of the products of digestion which is 
necessary to stop digestion in a solution increases with 
the amount of pepsin present. 
The relation between the para-peptones and peptones 
is not constant, and the former are present only at a pre¬ 
liminary stage in the production of the latter, and are 
