394 A COMPENDIUM OF 
thought of; at present it has been superceded 
by the alkaline carbonates of lime, soda and 
potassium. The white or albumin ovi is used 
to clarify mixtures and to act as an antidote to 
most of the metallic poisons, whilst the yellow 
(vitellus ovi) is employed for emulsifying the 
oils and forming an ingredient with those 
agents which are administered for a supporting 
treatment in all wasting diseases. The yolk 
forms an ingredient in the following officinal 
preparations: MIsTURA CHLOROFORMI, U. S., and 
the MISTURA SPIRITUS VINI GALLICI of the British 
Pharmacopeeia. 
Pepsinum, Pepsin.—~The digestive principle of 
gastric juice. Obtained by washing the stomach 
and scraping off the mucous membrane, which 
is then digested in distilled water, adding lead 
acetate, which throws down a precipitate of the 
metal and pepsin. This precipitate is subjected 
to the action of sulphuretted hydrogen, which 
body unites with the lead and leaves the pepsin 
m solution; this is then acidulated with lactic 
acid, after which the solution is evaporated and 
dried and mixed with starch or sugar of milk 
_ (although much of the pepsin is but the mu- 
cous membrane dried and powdered). This 
substance is from the stomachs of the calf (the 
young of the dos taurus), hog (sus scrofa), and 
the sheep (ovis aries). The pepsin made from 
the stomach of the hog is said to be stronger 
than that made from the calf and sheep, and is 
procured without the aid of lead; 5 or ro grains 
of pepsin (when carefully prepared) in solution 
and acidulated should readily dissolve 100 grains 
