Scientific American Supplement, No. 415, December 15, 1883Various
Science
Scientific American Supplement, No. 415, December 15, 1883
Various
Science -- Periodicals
The addition of bromides is superfluous, sometimes injurious. Bromides
in quantities, as added to ammoniacal pyro, would reduce the
sensitiveness to 1/10 or 1/20; will even retard the developing power
almost entirely.
Must a restrainer be resorted to, 1 to 3 min. of a 1:10 solution of
potassium bromide is quite sufficient.
* * * * *
THE PREPARATION OF LARD FOR USE IN PHARMACY.
[Footnote: Read at an evening meeting of the Pharmaceutical Society of
Great Britain, November 7, 1883.]
By Professor REDWOOD.
I have read with much, interest the paper on "Ointment Bases,"
communicated by Mr. Willmott to the Pharmaceutical Conference at its
recent meeting, but the part of the subject which has more particularly
attracted my attention is that which relates to prepared lard. Reference
is made by Mr. Willmott to lard prepared in different ways, and it
appears from the results of his experiments that when made according to
the process of the British Pharmacopoeia it does not keep free from
rancidity for so long a time as some of the samples do which have been
otherwise prepared. The general tendency of the discussion, as far as
related to this part of the subject, seems to have been also in the same
direction; but neither in the paper nor in the discussion was the
question of the best mode of preparing lard for use in pharmacy so
specially referred to or fully discussed as I think it deserves to be.
When, in 1860, Mr. Hills, at a meeting of the Pharmaceutical Society,
suggested a process for the preparation of lard, which consisted in
removing from the "flare" all matter soluble in water, by first
thoroughly washing it in a stream of cold water after breaking up the
tissues and afterward melting and straining the fat at a moderate heat,
this method of operating seemed to be generally approved. It was adopted
by men largely engaged in "rendering" fatty substances for use in
pharmacy and for other purposes for which the fat was required to be as
free as possible from flavor and not unduly subject to become rancid. It
became the process of the British Pharmacopoeia in 1868. In 1869 it
formed the basis of a process, which was patented in Paris and this
country by Hippolite Mege, for the production of a fat free from taste
and odor, and suitable for dietetic use as a substitute for butter.
Mege's process consists in passing the fat between revolving rollers,
together with a stream of water, and then melting at "animal heat." This
process has been used abroad in the production of the fatty substance
called oleomargarine.
Public-domain text, read in full here on John Shaqi.
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