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BRITISH PHARMACEUTICAL CONFERENCE. 
allowed to distil over with/the fat acids and water, and is concentrated by eva¬ 
poration. Price’s glycerine is well known at home and abroad for its great 
superiority and almost absolute purity, being of necessity free from inorganic 
matter. For, as Mr. Wilson has himself said, “ The only chemical agents used 
for decomposing the neutral fat, and separating its glycerine, are steam and heat, 
and the only agents used in purifying the glycerine thus obtained are heat and 
steam.” Mr. Wilson tells me that they are now making one ton per week of 
this pure medicinal glycerine, and, in order to ensure its perfect purity, it is fre¬ 
quently distilled five or six times. Like Bennett’s watches, Price’s glycerine 
leaves “nothing to be desired but the money wherewith to buy it.” 
It is in external remedies that the greatest field appears to be open for the 
further introduction of this substance in pharmacy, and I shall first call atten¬ 
tion to the compound of starch and glycerine known as “plasma.” It had long 
been thought desirable to find a substitute for fatty matters in ointments not 
liable to become rancid, and in 1858 Mr. Schacht, of Clifton, read a paper before 
the Pharmaceutical Society, in which he proposed for that purpose a mixture of 
seventy grains of starch with one ounce of glycerine, heated together to a tem¬ 
perature of 240° F. The product is a plastic mass well suited in most re¬ 
spects for the purpose, but has been objected to from its tendency to absorb 
moisture and become fluid by long exposure to the atmosphere. The inconve¬ 
nience arising from this source, however, might be easily obviated by keeping 
the plasma in air-tight jars, and dispensing it when necessary in wide-mouthed 
oottles. A much more serious hindrance to its general use is the fact that it 
costs about five times as much as the ordinary adipose basis of ointments. 
I have made a variety of experiments with “ plasma,” substituting in its com¬ 
position for the common wheat starch that of arrow-root, rice, potato, tous-les- 
mois, etc., all of which yield compounds differing from each other in some of 
their physical properties. The arrow-root plasma is beautifully transparent, but 
has an objectionable tenacity if more than sixteen grains to the ounce be used. 
On the whole, I prefer the tous-les-mois preparation to any other. The best 
mode of preparing this is, to rub together in a mortar fifty grains of tous-les- 
mois with one ounce of glycerine ; transfer this to a porcelain evaporating-dish, 
and heat over a gas flame to a temperature of 240°, constantly stirring with an 
ivory or wooden spatula. (A prescription recently came under my notice, in 
which an eminent surgeon had ordered starch and glycerine to be heated to this 
temperature over a water-bath! !) Some pharmaceutists recommend that the 
plasma should be kept at 240° for twenty minutes, but I see no advantages likely 
to accrue from this, and unless great care be taken to regulate the temperature 
the compound will become coloured, and will always be found to have dimi • 
nished considerably in weight, a result not at all satisfactory to the operator. 
If the application of heat be continued only long enough to burst the starch 
granules, or till the mixture becomes transparent, the loss will be about twenty 
grains to the ounce. The presence of a little water is not detrimental; indeed, 
I believe it improves the condition of the product, as it will be found more 
plastic and better suited for rubbing over the surface of the skin : even after it 
has been exposed to the air a few weeks, and thus absorbed more moisture. 
M. Surum, a French pharmaceutist, who has paid much attention to the subject, 
advises ten per cent, of water to be added to the starch previous to mixing it 
with the glycerine. I do not think plasma would be advantageously substi¬ 
tuted for fats in all ointments, but in those cases where there is a great tendency 
to rancidity, as in the Cer. Calam., Cer. Plumbi Acet., Ung. Zinci, etc. of the 
old Pharmacopoeia, and where the active ingredient of the ointment is soluble 
in glycerine, as in the Ung. Potass. lod., Ung. Aconitise, Ung. Atropiae, Ung. 
Belladonnse, Ung. Creosoti, and Ung. Veratriae of the British Pharmacopoeia, 
the plasmas appear preferable to the analogous ointments ; it also has the ad- 
