132 
BRITISH PHARMACEUTICAL CONFERENCE. 
The last and most important point is tlie filtering. Although straining through 
fine linen or flannel or felt, may be sufficient, when the consumption of the lar 
is rapid and not required for any very especial purpose, yet I cannot too 
strongly insist that if lard be required of first quality for such purpoBea; as 
ointments cold cream, pomades, and so on, it is absolutely essential that it 
should be filtered through paper, or some body that will effectually remove t ie 
numerous particles of membrane and tissue, which are always to be found in 
imperfectly prepared lard, and which are the main and often sole cause of . e 
rancidity of solid animal fats. This membrane or tissue has an unfortunate 
tendency to change, to become oxidized, and to set up a decomposing ac ion 
through^ the entire mass of fat, resulting in the generation of fatty acids and 
rancidity ; the presence of water materially expedites this decomposition, hence 
the necessity of re-melting to remove the last particles of water. _ 
• Bv following the process above indicated, I have succeeded m preparing lar , 
which will keep perfectly sweet and good for many months, even when the jar 
is constantly opened in the regular course of bustness and e ™ n ^ tel . th ® 
of a year, the lard has been much sweeter than nine-tenths of that to be had 
from the best makers, at the best prices. . . * -fiifororl 
There is here a specimen of the filtered lard, and also a specimen of filtere 
lard made from flare in an active state of decomposition, and when in an ex¬ 
tremely odorous condition ; from which you will see that the process of prepara¬ 
tion has nearly eliminated the rancidity, and it is in fact as good as a greater 
part of the best lards to be met with in commerce. ,, QT , 
1 The germ of success lies in filtration. If we resorted to this much oftener 
than we*usually do, not only as regards lard, but with many ointments and 
other analogous compounds, we should derive P m ®nw w 
great superiority of the results over mere straining through muslin, flannel, or 
^ To strain in these cases is to invite inferiority, to filter is to secure superiority, 
lf lii conclusion 11 ’ I may say the cost of filtered lard varies from 10 d. to Is. 3d. 
per pound, according to the time of year, but of course the price may be modi¬ 
fied in different localities by local circumstances. 
THE APPLICATION OP SPECTRAL ANALYSIS 10 
PHARMACY. 
BY W. W. STODDART, F.G.S., F.C.S. 
Perhaps the most startling discoveries of the present day have been those 
which bear some relation to experimental physics, and more particularly to that 
branch which treats of optical phenomena. < ! 
Not very long ago the supposition of a close relationship between light and 
chemiJl action would have been ridiculed, and indeed was so. Now, however, the 
education of a chemical student must include the fundamental laws and pi o per- 
ties of light. The chemist, in his analyses, is constantly invoking the aid of light 
in some way or other to help him in revealing the hidden secrets of nature. Some¬ 
times the magic touch of a polarized ray will point to each individual granule 
of starch as it lies hidden by a multitude of other cells; nay, more it will even 
tell him the name of the plant from which it was derived ; andlai it thiswere 
not enough, the solar rays themselves are actually compelled to reveal to the 
student their nature and the composition of the sun from ^i c t ‘ h ey radiate 
Within the last few years the labours of Kirchhoff, Lunsen, feorby, and 
Huggins have been richly rewarded by fresh victories from the study of spectra 
