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ON GLYCERIN. 
ART. XXXII.— ON GLYCERIN. 
By Samuel E. Shinn. 
(An Inaugural Essay.) 
Although glycerin has for a considerable time been 
known to the chemist, its application, either in medicine or 
pharmacy, has been very limited until quite a recent period. 
It had indeed been occasionally employed to give softness 
to pills or ointments, and had also enjoyed some reputation, 
as an emollient application to the skin. But within a short 
period, it has attracted much attention, on account of its effi- 
cacy in cases where deafness has been caused by the in- 
duration of the wax of the ear; and it is an admirable 
remedy, as it does not thicken by oxidation, but rather 
absorbs water from the air, and has a tendency to keep the 
parts to which it is applied, continually moist. This dis- 
position was shown, by placing a drop of glycerin upon a 
smooth surface, and exposing it to the air ; it gradually- 
increased in bulk, its consistence became much thinner, and 
remained so as long as any observation was made upon it. 
Glycerin has shared the fluctuations of opinion, incident to 
all new remedies, but if nothing should be discovered to 
counteract the good impression it has already created, it 
will, perhaps, eventually become generally employed, and 
be recognized and adopted as officinal in our Pharma- 
copoeia. 
Glycerin exists in most of the fixed oils and fatty sub- 
stances, combined with various acids, from which it can be 
separated by the process of saponification ; the acids leave 
their old combination, to unite with the basic principle, and 
the glycerin is set at liberty. 
The following is the most common method of obtaining 
it. Lead plaster is made as directed by the U. S. Pharma- 
copeia. While yet fluid, a quantity of hot water is thrown 
in, and mixed intimately with the plaster. It is then al- 
lowed to separate, and the liquid being drawn off, is 
