13S 
BRITISH PHARMACEUTICAL CONFERENCE. 
Liq. Ferri Perchlor. —Blue, green, and violet strongly absorbed. 
Liq. Ferri Permit. — Blue and green and violet strongly absorbed. 
Liq. Ferri Persulph. —Green very much darkened, but not entirely, as in the 
other two iron solutions. Blue and violet entirely absent. 
Sol. Potass. Bichrom. —Spectrum only visible to two-thirds the distance be¬ 
tween E and F. All the remainder absorbed. 
Sol. Pot. Fermanfjan. —Well-known and exquisite spectrum. Five well- 
marked lines between F and D. The first thinner than the other four. 
Syr. Rhoeados. —Yellow, green, blue, and violet absorbed, even when much 
diluted. 
Vinum Fend Citratis. —Extreme end of red at commencement of spectrum 
green ; blue and violet absorbed. Red and orange only transmitted. 
Vin. Ferri. —Red and orange only transmitted. It is a peroxide of iron 
spectrum. 
Vin. Ipecac. —Green darkened, blue and violet absorbed. 
ON" SYRUP OF PHOSPHATE OF IRON. 
BY THOMAS B. GROVES, F.C.S. 
In the latter part of 1867 I found, in my cellar, a bottle of syrup of phosphate 
of iron that had lain long unobserved, and had acquired a dark sherry colour. 
A considerable amount of a precipitate of a red colour had formed in it, and 
encrusted the bottom of the vessel. I therefore commenced some experiments, 
with the view of ascertaining the exact nature of the precipitate, of devising 
means for removing the colour of the syrup, and of preventing the re-acquisi¬ 
tion of such colour. 
I was not unmindful of Mr. Umney’s paper on the same subjects, but, after 
reading it carefully, determined on proceeding independently. 
The precipitate was composed of two layers,—the upper layer crystalline in 
structure, red-brown on the upper, white on the under surface; the underlayer 
white and amorphous. The two separated by washing, reacted similarly, proving 
themselves to be a combination of peroxide of iron with ordinary phosphoric 
acid, and agreeing chemically with the white precipitate produced artificially in 
the syrup by the use of oxidants. 
Analysis furnished a formula closely corresponding with (Fe 2 0 3 ,P0 5 -f-aq.), 
the acid being a little in excess. The substance was probably not of a definite 
character, so comparisons were instituted between it and various phosphates of 
peroxide of iron prepared artificially as follows:— 
No. 1. By adding phosphate of soda in excess to perchloride of iron. 
No. 2. By adding perchloride of iron to excess of phosphate of soda. 
No. 3. By adding perchloride of iron to excess of phosphate of soda, pre¬ 
viously acidulated with phosphoric acid. 
No. 1 was a body of indefinite character, the nature of the phosphate neces¬ 
sarily varying with the varying conditions of the mixture—acidity, neutrality, 
or alkalinity, at different stages of the precipitation. It presented the appear¬ 
ance of a fawn-coloured powder. It was not analysed. 
No. 2 was in colour pale foxy-red. Analysed, it gave the formula (5Fe 2 0 3 , 
6P0 5 -f-aq.). 
No. 3 was colourless. After long-continued washing with water, it still re¬ 
acted acid to test-paper. Analysed, it gave the formula (2 Fe 2 0 3 , 3 P0 5 + aq.) 
These experiments were suggested by reading Mr. R. Warington’s paper on 
the Phosphates of Calcium (Journ. Ch. Soc. vol. iv. N.s.). 
