February 3, 1872.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
625 
in a higher degree than any other substance the 
active principle of the aconite. 
As various authors have spoken of a narcotic prin¬ 
ciple contained in the aconite, M. Duquesnel has 
sought to obtain such evidence as would enable him 
to verify or disprove its existence. By concentrat¬ 
ing the solution containing the excess of bicarbonate 
of soda after all the aconitine has been removed, he 
obtained an extract or residue representing all the 
principles of the alcoholic extract of aconite root, 
less the aconitine and the resinous matter insoluble 
in water removed by the filter. After drying this 
alkaline residue, and mixing it with a little pure 
silica in order to divide it more easily, it was agi¬ 
tated several times with sufficient chloroform to 
carry off the last traces of aconitine, dissolved in al¬ 
cohol and again evaporated, when a yellowish deli¬ 
quescent extract was obtained. This extract still 
contained an active principle, for, when administered 
to a bird, it produced a profound slumber, lasting 
several hours, without anaesthesia, followed by a 
complete recovery ; but when a larger dose was ad¬ 
ministered, the slumber was followed by death. The 
author proposes to investigate this matter further, in 
order to ascertain whether these effects are due to a 
substance different from aconitine, such as Hubscli- 
mann’s napelline, or to traces of aconitine. 
(To be continued.) 
XYLOL. 
This hydrocarbon is likely to become of great im¬ 
portance, if its application in cases of smallpox is 
really followed by such good results, as have hither¬ 
to been obtained at Berlin. 
The Berlin Klinisclie Wochenschrift states that 
Dr. Zuelzer, Senior Physician at the Charite Hos¬ 
pital, had there administered xylol in cases of small¬ 
pox, with the most complete success. It is given in 
doses of from 3 to 5 drops for children, 10 to 15 
drops for adults, every hour to every three hours. 
It is harmless, because as much as a teaspoonful at 
a time has been taken. The most convenient form 
of taking it is in capsules, as already supplied by a 
Berlin firm, and containing 3, 5, 8, and 12 drops 
each. 
The specific action is not yet clearly defined, but 
early information on this point is promised. The 
theory at present is that xylol is taken up by the 
blood, and acts as a disinfectant. 
The absolute purity of the xylol is important, 
as toluol and other analogous compounds do not 
possess this peculiar action, and it seems there are 
some practical difficulties in obtaining xylol abso¬ 
lutely pure. 
Xylol, or xylene, C S H 10 , was first separated from 
coal naphtha by Dr. Hugo Muller; it is obtained 
by fractional distillation until a distillate is obtained 
of about 110° C. boiling-point; this is mixed with 
sulphuric acid, which dissolves xylol, forming xylol 
sulphuric acid; this acid is decomposed by dry dis¬ 
tillation, and the xylol thus obtained is further pu¬ 
rified. 
Bure xylol is colourless, it has a faint odour, 
somewhat like benzol, but different, boiling-point 
139° C., specific gravity 800. 
CjjaptcK for Sttcnfs. 
CHEMICAL NOTES TO THE PHARMACOPOEIA. 
BY WILLIAM A. TILDEN, D.SC. LOND. 
DEMONSTRATOR OF PRACTICAL CHEMISTRY TO THE 
PHARMACEUTICAL SOCIETY. 
Potassve Prussias Flava. —Ferrocyanide of po¬ 
tassium. K4 FeC 6 N 6 , 3H 2 0. [§ A salt obtained 
by fusing animal substances, such as the cuttings of 
horns, hoofs and skins with carbonate of potash in 
an iron pot, lixiviating the crude product with water, 
and purifying the salt by crystallization.] 
When potassium or sodium is heated strongly 
with a substance containing carbon and nitrogen, a 
cyanide is formed. When the animal matters are 
fused with carbonate of potassium, the potassium is 
reduced probably to the metallic state, and by im¬ 
mediate union with carbon and nitrogen from the 
organic matter cyanide of potassium is produced. 
The ferrocyanide is not formed until the mass is 
treated with cold water, when the cyanide dissolves 
the iron with which it is in contact; a certain 
amount of hydrogen gas is then evolved, though the 
greater part by absorption of oxygen from the air is 
converted into water, 
6 [KCN] + Fe + 2FI 2 0 
= K 4 F e Cg N 6 + 2KHO + H 2 . 
A considerable loss of material occurs at every 
stage of the process; and several other minor re¬ 
actions go on at the same time, being chiefly due to 
impurities in the pearlash. 
Ferrocyanides contain the elements of c} r anide of 
iron and some other cyanide, but they do not pre¬ 
sent the properties of simple c} 7 anides which such a 
combination would have. On the contrary, the iron 
is united with the carbon and nitrogen to form a 
compound quadrivalent radicle (FeC 6 N 6 ) iv , in which 
the iron cannot be recognized by ordinary precipi¬ 
tant?. 
An important difference between the two classes 
of salts exists in the fact that, whilst all the cyanides, 
—whether single, that is, containing one metal, or 
double, containing two,—are fearfully poisonous, the 
ferrocyanides are harmless, except, of course, in case 
of compounds containing poisonous metals. Even 
then, in consequence of their general insolubility, 
they are not very active. 
Ferrocyanide of potassium crystallizes in large 
yellow four-sided tables, which are tough, but cleave 
easily. [§ The aqueous solution precipitates deep 
blue (Prussian blue (Fe 2 ) 2 (FeC 6 N 6 ) 3 ) with persul¬ 
phate of iron, brick red with sulphate of copper, 
and white with acetate of lead. Heated with diluted 
sulphuric acid, hydrocyanic acid vapours are evolved.] 
See Ac. Hydrocy. Dil. Heated with strong oil of 
vitriol, it undergoes a different decomposition, in 
which the elements of water take part. 
I\ 4 FeCgNg + 6 H 2 S0 4 + 6H 2 0 
= 2Iv 2 S0 4 + FeS0 4 + 3 [(NH 4 ) 2 S 0 4 ] ffiCCO. 
This is the process of Fownes for preparing pure 
carbonic oxide. 
When ferrocyanide of potassium is melted by the 
application of heat it is resolved into cyanide of po¬ 
tassium, which remains unchanged, and cyanide ot 
iron, which is decomposed with evolution ot nitrogen 
gas and deposition of a compound of carbon and 
