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XLVI. An Account of some Experiments on the Action of 
Iodine on volatile and fixed Oils, &c. By EpMunpD Davy, 
Esq. Professor of Chemistry and Secretary to the Royal Cork 
Institution. 
To Dr. Tilloch. 
DEAR Sir,—L BEG to send you for insertion in your very use- 
ful Journal, an Account of some Experiments I have made on 
the Action of lodine on volatile and fixed Oils, &c. With sincere 
good wishes for your health and happiness, 
} remain, dear Sir, 
With great respect, yours very truly, 
EpMuND Davy. 
Being lately engaged in making some experiments with iodine, 
I was led to try its action on different volatile and fixed oils, &c. 
The results I obtained are, I presume, novel; and a brief account 
of them will make some addition to our present knowledge of the 
agencies of this singular substance. 
Action of Iodine on Oil of Turpentine. 
When a small portion of iodine is brought in contact with a 
few drops of turpentine, a violent action takes place, considerable 
heat is generated, and part of the iodine rises invapour. In one 
instance, when I put less than a grain of iodine into a small 
curved tube, and poured a little turpentine on it, the heat pro- 
duced was very sensible to the hand. In another case, when I 
added about ten drops of turpentine te about a grain and. half 
of iodine, in a small phial, the action was very violent ; a portion 
of the turpentine appeared to be decomposed, it became tena- 
cious, adhered to the glass, and was of a dark olive-brown co- 
lour. Turpentine is a very good solvent of iodine, and dissolves 
a considerable quantity of it with much greater facility than al- 
cohol does. When iodine is put into turpentine, a hissing noise 
is produced, the iodine quickly dissolves, and forms a solution of 
a reddish yellow colour, which, when very concentrated, is dark 
yellowish-brown. This solution is not affected by water, or by 
the mineral acids when diluted, or by the greater number of 
metallic salts. The nitrates of silver and mercury, however, de- 
compose it, and the iodes of silver and mercury are formed. By 
dissolving iodine, turpentine, to a certain extent, loses its cha- 
racteristic odour and volatility ; the solution, when weak, does 
not affect vegetable colours, or tarnish polished silver; but 
when strong, it gives a reddish-brown tint to litmus, and a dull 
yellow to silver and tin. It stains linen yellow, and gives to starch 
a slight yellowish tint. Rectified sulphuric ether and alcohol 
; combine 
