260 
PHARMACEUTICAL MEETING. 
Wednesday , November 6th, 1867. 
ME. G. W. SANDFOKD, PRESIDENT, IN THE CHAIR. 
The Minutes of the previous Meeting having been read, the following 
DONATIONS TO THE LIBRARY AND MUSEUM 
were announced, and the thanks of the Meeting given to the respective 
donors:— 
The Calendar of the Royal College of Surgeons for 1867: from the College,—The 
Calendar of the University College for 1867-8 : from the College,—Grew’s Anatomy of 
Plants : from Mr. R. Goodwin Mumbray,—Hydrologie Generate: ou dissertation sur la 
nature, les qualites et les usages des Eaux naturelles et artificielles, minerales et potables. 
Par Antonio Alves Ferreira, M.P.S. : from the Author,—Microscopic Examination of 
Urinary Sediments, with Plates : from Professor Attfield,—Collection of British Plants: 
from Mr. Isaiah Tansley,—A New Farina: from Chapman and Co. 
Dr. Attfield, referring to the specimen of farina on the table, which had 
been placed there by one of their members, said its peculiar feature consisted in 
the large proportion of flesh-farming constituents it contained. In this respect 
it stood very high as compare i with other farinaceous substances. 
The following papers were read :— 
ON THE PRESERVATION OF SYRUP OF IODIDE OF IRON. 
BY WILLIAM A. TILDEN, F.C.S., 
DEMONSTRATOR IN THE SOCIETY’S LABORATORIES. 
Several plans have been suggested with the hope of rendering this important 
medicine less liable to alteration ; of these the most notable consists in intro¬ 
ducing into the syrup a coil of clean iron wire. Experience, however, shows 
that the proposed remedy is ineffectual, the suggestion being founded, as I be¬ 
lieve, upon a misapprehension of the nature of the change. The brown colour 
and precipitate developed are not due to periodide of iron, but to the compound, 
the formation of which is represented by the accompanying equation :— 
2 Fel 2 + H.O + O = Fe 2 I 4 2HO* 
With reference to the production of the change, I think it cannot fail to have 
been remarked, that it proceeds far more rapidly when the syrup is exposed to 
the diffused light of day, than when preserved in total darkness. Light, though 
it cannot, in certain cases, of itself effect chemical metamorphosis, is yet 
capable of accelerating in a marked manner the action of various agents, par¬ 
ticularly atmospheric oxygen. Quite different, however, in this instance is the 
apparent effect of the direct rays of the sun. It has been observed, I believe, 
with reference to syrup of iodide of iron, that when exposed to direct sunlight’, 
though coloured by previous oxidation, it seems to recover its original appear¬ 
ance. This result I believe to be brought about by conversion of part of the 
hydrogen of the sugar into water by the oxygen which had been previously 
* 8o far as I am aware, this body has not been analysed, but the corresponding compound, 
obtained in the same way by exposure of an aqueous solution of ferrous chloride to the air, 
is well known. Its formula is Fe 2 C2 4 H 2 0 2 . 
