114 
ON PEP SINE. 
not retain its original form; being hygrometric in the highest degree, it readily absorbs 
humidity from the atmosphere, becomes viscid, soon liquefies, and consequently returns 
into the category of nitrogenous bodies, which, in the presence of water and a slightly 
elevated temperature, enter into putrid decomposition. In this state pepsine loses all 
its digestive properties, and is variable from the augmentation of weight due to water, 
the medicinal properties diminishing accordingly. 
How is the hygrometricity to be remedied? The inert powder already mentioned 
solves this problem, since, as soon as it is intimately incorporated with the extract, this 
ceases to attract humidity, and preserves a granular pulverulent form. Starch is the 
substance which best preserves pepsine from decomposition without injury to its thera¬ 
peutic action; most other vegetable powders, either from the tannin they contain or 
from some catalytic force arising from their porosity, destroy rather than preserve it. 
The admixture of starch gives to pepsine the most convenient form. Corvisart has 
noted all the conditions that it ought to present in -practice, viz.:— 
First. The action of the gastric juice is the dissemination of its active principle 
amongst the food, so the pepsine in powder imitates the natural action by the dissemina¬ 
tion of its granules; on the contrary, the pills, etc., of pepsine have an opposite effect, 
and frequently pass into the intestines without action. 
Secondly. The gastric secretion does not pass into the stomach by the mouth before 
action ; so, the pepsine powder, taken in wafer paper, commences to act in the stomach, 
and thus fulfils the physiological design; whilst the dragees or pepsine lozenges, which 
dissolve in the mouth, are little in accordance with it. 
Thirdly. The gastric juice is secreted drop by drop, slowly and successively ; so each 
granule of starchy pepsine evolves, in dissolving, its active principle, thus imitating the 
formation of the natural fluid. This is not the case with the solutions of pepsine. 
When administered, in cases where the stomach is irritable, under the form of wines and 
syrups, it is sometimes borne with diPiiculty. 
These conditions, which demand a preparation pure, unalterable, possessing always 
an invariable digestive power, are fulfilled by the “ Pepsine Araylacee,” or medicinal 
pepsine, which imitates the formation of the gastric juice, its gradual secretion, and its 
slov/ and continual dissemination amongst the food. 
Mode of Extraction .—A certain number of calves’ or sheep’s rennets are taken from 
the animals as soon as killed, thoroughly washed with water; the mucous membrane, 
which contains the peptic glands, is scraped, macerated in water at 10° to 15° C. for 
twelve hours; the pepsine in the solution is then precipitated by acetate of lead, allowed 
to settle, and the supernatant liquid poured off; a current of sulphuretted hydrogen is 
passed through the semi-liquid deposit, which precipitates the lead in the form of sul¬ 
phide ; the pure pepsine remains in solution with the free acetic acid ; it is then filtered, 
and finally evaporated to dryness at a uniform temperature of 40° C. 
The next operation is the trial and determination of the dose of the pepsine. To de¬ 
termine the quantity of digestive power contained in a given weight, three samples are 
taken from the mass, the first of 25 centigrammes, the second 50 centigrammes, and the 
third 75 centigrammes. Each is placed in a separate vessel, with the addition of, first, 
25 grammes of water; secondly, acid (lactic or other acid), a sufficient quantity to sa¬ 
turate 17 centigrammes of pure caustic potass (equivalent to the acidity of the gastric 
juice); thirdly, fibrine obtained from calves’ blood, washed and strongly pressed in a 
cloth. The three vessels are then placed in a stove, and maintained at a uniform tem¬ 
perature of 45° C. for twelve hours. The sample in which the fibrine has been dissolved 
and converted into pure peptone (albuminose), not precipitable by nitric acid, is the 
normal and therapeutic dose of the pepsine. 
But as the weight of pepsine necessary to obtain this regular power varies incessantly, 
sometimes 25, sometimes 50, or 75 centigrammes, whichever it may be, at each opera¬ 
tion, sufficient starch is added to make the weight 1 gramme, so that each gramme con¬ 
tains invariably a uniform digestive power, the quantity of starch alone varying. No phy¬ 
sical or chemical characteristics distinguish active pepsine from that which is inert, nor 
from other nitrogenous bodies more or less allied; the only important quality being its 
digestive pow r er, the test with fibrine is the only method of determining their value, all 
preparations, whatever may be their aspect and chemical reactions, are not pepsine if 
they do not answer to it. The digestive characteristic consists in that pepsine, in twelve 
hours, dissolves fibrine, and converts it into peptone, not precipitable from its solution 
