Preparation

The following process has been indicated by Mr. Gaultier de Claubry.

The mercury is dissolved by nitric acid in a glass flask with a short neck; the liquid must fill it quite 2/3 ds, as it disengages a great quantity of nitrous vapors. The flask is placed under a chimney with a good draught. If there be no chimney the operation is performed in the open air, and a weak elevation of temperature is necessary. The proportions used are generally 1 1/2 pounds of mercury and 18 pounds of acid.

The dissolution is divided into 5 glass flasks to operate the mixture with alcohol. For this purpose, when the dissolution has a yellowish shade, the mercury having disappeared, leave it to cool for 8 or 10 minutes, and pour it into 17 the flasks. In the 5 flasks distribute 8 or 10 quarts of alcohol at 95°; often a very quick reaction is produced, and the fulminate de-posits. The operation is achieved when it does not disengage any vapor, and when the liquid becomes limpid. In many cases it is necessary to put a little fire under the flask in order to determine the reaction. In both cases there is a great disengagement of vapor, the action of which on the animal economy is very strong. It can, however, be condensed with a receiver, into which will be found a certain quantity of mercury, alcohol, a kind of ether, and several other products.

When the fulminate is well deposited, separate the mother water, and reunite it in two flasks in which a new quantity separates.

Pour the fulminate into a wooden bowl, and after decantation wash it with about 1/4 of its volume of cold water.

The most convenient process is the one adopted in England, and indicated by Dr. Ure. It gives the largest proportion of fulminate.

Dissolve at a gentle heat 100 parts in weight of mercury in 1000 parts of nitric acid at a spec, grav. 1.40; pour the dissolution, previously carried to 131°, into 830 parts of alcohol of a density of 0.83. By measuring it takes one vol. of mercury, 7 1/2 of nitric acid, and 10 of alcohol.

Dissolve the mercury in the acid in a tubulated glass retort, the neck of which communicates with a glass receiver surrounded by cold water, to collect the distilled vapors.

The condensed liquid is poured back into the retort. When all the mercury is dissolved, and the temperature is at 131°, pour slowly the solution into the alcohol contained in a glass flask, the volume of which must be at least six times as great as the liquor it has to contain. A few minutes after there begins, from the bottom of the flask, a light disengagement of gas, the quantity increases by degrees till it produces a quick ebullition; it disengages by the neck of the flask a thick and whitish vapor forms, the greater part of nitrous ether, easy to inflame.

Some have tried to condense the part of the mercury mechanically carried away by this vapor; for this purpose they passed the vapor through a solution of subcarbonate of soda; but as this process rendered the formation of the fulminate more difficult, and altered its quality, it has been abandoned.

When the ebullition and disengagement of vapors have stopped, throw the whole on a filter, and wash the precipitate with pure and cold water until the washing water has no action on litmus paper. Take the filter, spread it upon a plate of copper heated by steam below 212°. Divide the dry precipitate into portions of 1 1/4 to 1 1/2 drachms; shut it up in a paper, and afterwards in a large glass bottle.

By the above process Ure obtains from 100 parts in weight of mercury, 130 parts of fulminate; then as 100 parts of mercury corresponds to 142 of fulminate, the loss is of 8 1/2 per cent of the mercury employed.

On a warm, clear day, one man with two assistants can make, and partially wash, one hundred pounds of fulminate in 10 hours.