152 
pharaoh’s serpents. 
thus :—Berlin Bitter Oil, “ Corn Brandy Cummin Oil,” JDantzic Goldwasser 
Oil, and Spanish Bitter Oil. The compound ethers are applied to the same 
purposes tor which they are used in England, that is, to counterfeit, with 
more or less success, the natural flavours of wines and other alcoholic beve¬ 
rages. They consist, as regards the specimens in Messrs. Remme’s collection, 
of^organic ethers and aldehydes combined with essential oils. These shown 
are essences of arrack, brandy, rum, sherry, and “muscat lunel.” The last 
apparently consists of acetic ether and oil of neroli. The rum essence is, 
as far as I can analyse it by smell, aldehyde and creasote; the brandy es¬ 
sence, pelargonic and acetic ethers with vanilla. 
Cigars “ impregnated with iodine,” are shown by Eckert (Frankfort-o.-M.). 
I think I have now noticed all the products in the Dublin International 
Exhibition, which appear to me likely to interest the readers of the journal, 
or to merit record in its pages. I have only, as I bring nay report to a con¬ 
clusion, to thank those who have so kindly afforded me information, and to 
express my obligations to the exhibitors and their agents for. the uniform 
courtesy and often painstaking attention which I have received at their 
hands. 
PHARAOH’S SERPENTS. 
TO THE EDITOR OF THE PHARMACEUTICAL JOURNAL. 
Sir,—A very curious toy is now being sold in Paris, under the name of 
Pharaoh’s Serpent. As this toy really constitutes an interesting chemical expe¬ 
riment, perhaps an account of it may prove interesting to your readers. 
It consists of a little cone of tinfoil, containing a white powder, about an inch 
in height and resembling a pastille. This cone is to be lighted at its apex, when 
there immediately begins issuing from it a thick serpent-like coil, which con¬ 
tinues twisting and increasing in length to an almost incredible extent. The 
quantity of matter thus produced is truly marvellous, especially as the coil which 
so exudes is solid and may be handled, although, of course, it is extremely light 
and somewhat fragile. 
Having a little of the white powder, with which the cones are filled, placed at 
my disposal by a friend, I submitted it to analysis and found it to consist of 
sulphocyanide of mercury. This salt, when heated to a temperature below 
redness, undergoes decomposition, swelling or growing in size in a most remark¬ 
able manner, and producing a mixture of mellon (a compound of carbon and 
nitrogen) with a little sulphide of mercury. The resulting mass often assumes 
a most fantastic shape, and is sufficiently coherent to retain its form ; it presents 
a yellow colour on the exterior, but is black within. The “serpent” shape of 
course results from the salt being burnt in a cone of tinfoil. 
Both the mercurous and mercuric sulphocyanides decompose in the same 
manner ; but the mercuric salt, containing more sulphocyanogen, seems capable 
of furnishing a larger quantity of mellon, and is the one used in the French 
serpents. A solution of pernitrate of mercury is readily precipitated by sulpho¬ 
cyanide of ammonium, and the mercuric sulphocyanide may be easily so pre¬ 
pared. It is best to use the mercurial solution as strong as possible, and to 
keep it in excess throughout the precipitation. Solution of perchloride of mer¬ 
cury is not so easily precipitated as the pernitrate, probably owing to the 
solubility of the mercuric sulphocyanide in the chlorides. 
Perhaps I may be excused for adding that sulphocyanide of ammonium, suit¬ 
able for the above purpose, may be very easily and economically prepared, as 
follows:—One volume of bisulphide of carbon, four volumes of liq. amrnon. fort., 
