CHEMISTRY OF PEPSIN. 
47 
recently that, under its new form, it has been reintroduced 
as a remedy. It occurred to M. Boudault that if he could 
separate the active constituent from the inert and useless 
substances associated with it in the gastric juice, he would be 
able to produce not only a much less disagreeable medicine, 
but one of greater certainty of action. This he now effects 
in the following manner:—The stomachs of sheep are in¬ 
verted and washed under a very gentle stream of cold water, 
and with a blunt knife the pepsin-secreting follicles are 
scraped off and beaten in a mortar with a small quantity of 
distilled water. The liquid filtered from this, being next 
treated with a solution of acetate of lead, gives a copious 
white precipitate—peptate of lead—which is collected on a 
filter, and after being freed by washing from all excess of the 
lead salt is diffused through a small quantity of water. The 
suspended precipitate is next decomposed bv a stream of 
sulphide of hydrogen, sulphide of lead and pepsin being pro¬ 
duced. The former is separated by filtration, and the latter 
remains in solution. Now r , if this solution of pepsin were 
simply to be evaporated to dryness, all due precaution not to 
exceed a temperature of 100 being observed, the product 
would be a gummy, very deliquescent mass, prone to decom¬ 
position, and altogether unfit for medicinal use. To obviate 
these inconveniences and give the pepsin a permanent form, 
M. Boudault mixes with the solution, when evaporated to 
the consistence of a thick syrup, starch powder in certain 
fixed proportions. This constitutes the c<r neutral pepsin” 
recommended by the inventor in cases where dyspepsia is 
complicated with abnormal acidity of the stomach. But for 
cases where there is no undue acidity a pepsin powder is 
prepared, to which lactic acid is added in such proportion as 
will give the degree of acidity which canine gastric juice is 
found to possess. There are also combinations of pepsin 
with morphia, strychnia, and iron ,—olla podrida , which I 
cannot but look upon as being not only unchemical, but 
calculated to lead to false deductions as to the value of 
pepsin itself. 
Pepsin should be taken between thin slices of bread, not 
either before or after, but—in imitation of the natural 
secretion —at a meal. As any excess of temperature beyond 
120° Fahr. totally destroys its digestive property, hot 
fluids should never be taken either immediatelv before or after 
its exhibition; and as it is decomposed by alcohol, if spi¬ 
rituous liquids be used at all they should be very much 
diluted. 
