TRANSACTIONS OF THE PHARMACEUTICAL SOCIETY. 
could not enter upon. They could not decide upon the therapeutic value of 
a medicine. 
The Chairman suggested that Mr. Squire should induce a medical friend 
to make some experiments with the extract, and report the results to the 
Society. 
NOTE ON THE PRESERVATION OE THE OXIDE OF 
MERCURY OINTMENT. 
BY THOMAS B. GROVES, F.C.S. 
I am surprised to observe that neither Mr. Barber nor those who discussed 
his paper, appear to have remembered anything of my experiments on the preser¬ 
vation of oxide of mercury ointment, a detail of which, under the title of “ Ran¬ 
cidity of Fats,’’ was presented to the Bath meeting of the British Pharmaceu¬ 
tical Conference. 
I there pointed out that the addition of a minute quantity of certain essential 
oils would entirely prevent both reduction of oxide and rancification of the 
fatty excipient. 
I have just examined some specimens I made December 5, 1861, and find that 
several of them are looking as well as ever, and have no smell of rancidity. 
Those perfumed with clove or pimento, two drops to the ounce, keep best,—in 
fact, seem everlasting. Pimento is in my opinion to be preferred for many 
reasons, to clove. I have added that oil to ceratum calaminse and ung. zinci 
also, with the best results, but the latter must be made with Hubbuck’s oxide, 
in consequence of the P. L. preparation striking with the oil a faint yellow 
colour. 
I may add that my customers have never complained of, nor indeed noticed, 
that I am aware of, the odour of these ointments, the medical effects of which 
are in no way modified by aromatization. 
Weymouth, December 4, 1865. 
Mr. Reynolds, of Leeds, exhibited a very beautiful collection of models 
of fungi, which he had obtained from Paris. They were of Italian manufac¬ 
ture, and very correctly illustrated all the different varieties of fungus that 
were found in different countries. 
OBSERVATIONS AND EXPERIMENTS ON THE PHYSICS OF 
FILTRATION. 
BY JOHN ATTF1ELD, PH.D., F.C.S., 
Director of the Laboratories of the Pharmaceutical Society of Great Britain. 
One, somehow, generally associates nature with the country ; and truly there 
is much excuse for so doing, for in towns one is so surrounded with the produc¬ 
tions of the art of man, and one’s mind is so occupied with one’s daily pursuits 
that leaves and flowers and the starry sky are seldom thought of, and by reason 
of the dust and smoke we raise, still less seldom seen. And of all the busy 
