Art. XVI. Cautions regarding Fulminating Powders.

Fulminating Mercury.

During a late lecture in the laboratory of Yale College, a quantity of fulminating mercury, probably about 100 or 150 grains, lay upon a paper, the paper lay on a small stool, which was made of pine plank, one inch and a half thick; a glass gas receiver, 5 or 6 quarts capacity, stood over the powder, as a guard, but without touching it, and stool and all stood on one of the shelves of the pneumatic cistern, surrounded by tall tubes and other glasses, several of which were within 6 or 8 inches. A small quantity of the fulminating powder, at the distance of a few feet, was merely flashed, by a coal of fire, but without explosion. In a manner, not easily understood, the whole quantity of powder under the large glass instantly exploded with an astounding report; but the glass was not exploded—it was merely thrown up a little; in its fall it was shattered, and broke a glass which it hit, but no fragment was projected, and none of the other contiguous tubes and glasses were even overset, nor were any of a large audience, and some of them very near, even scratched; but the plank, one and a half inch thick, on which the powder lay, had a hole blown quite through, almost as large as the palm of one's hand. This is a striking instance to prove that the initial force of this powder, when exploded, is very great, but that it extends but a very little way. If it be strewed through a glass tube of three-fourths of an inch in diameter, and exploded by a coal of fire or hot iron, the tube may be held in the naked hand, and the powder only flashes without breaking the tube, and merely coats it over inside, and that very prettily, with the revived quicksilver.

Fulminating Silver.

Chemists are too well acquainted with the tremendous energy of this preparation, to make any comment upon its powers necessary. Unhappily, however, it is now made a subject of amusement; it is prepared for sale by those who know nothing of it, except as a nostrum, and it is bought by others who have not even this degree of knowledge. It is true it is put up in small quantities, in the little toys called torpedoes, and, if exploded one by one, they will ordinarily do no harm; but as they fall into the hands of children, we can never be secure that they will be discreetly used.

A very severe accident, from the unexpected explosion of this substance, occurred some years since in the laboratory of Yale College. (See Bruce's Journal, Vol. I. p. 163.) And, notwithstanding that this occurrence was well known in New-Haven, the same accident, only under a severer form, has again occurred in that town.

A man who had bought the secret of making fulminating silver, had prepared as much as resulted from the solution of one ounce and a half. Apparently, in a great measure, unaware of the nature of the preparation, he had placed it, unmixed with any thing, on an earthen plate, which stood on a table; his wife and children being around, he sat down to distribute the powder upon several papers which he had prepared for the purpose; sand and shot are mixed with the powder in the papers for the purpose of giving momentum, and of producing attrition when the torpedo is thrown, in order to ensure its explosion. Probably also the sand, looking not very unlike the powder, may be intended to screen it from view, and thus to preserve the secret, should the papers be opened. The unhappy man no sooner touched the fulminating silver with a knife, than it exploded with its usual violence; the table was split in two; blood issued copiously from every part of his face, not from wounds, for it does not appear that the fragments hit him, but, according to the opinion of a competent judge, the blood was actually forced through the pores of the skin by the power of the explosion, which very nearly destroyed his eyes. He suffered immensely, but now, at the end of eight months, sees partially with one eye, but the other is nearly, if not quite, destroyed.

Should not the tampering with such dangerous substances by ignorant people be prevented by law?

In a late lecture in the laboratory of Yale College, some fulminating silver, on the point of a knife, was in the act of being put upon a copper-plate connected with one pole of a galvanic battery in active operation, the other pole was not touched by the experimenter; but it seems that the influence which was communicated through the floor of the room was sufficient instantly to explode the powder, as soon as the knife touched the copper-plate; the knifeblade was broken in two, and one half of it thrown to a distance among the audience.

Recently also, we are informed, in one of the foreign journals, that a man in England, who accidentally trod on a quantity of fulminating silver, had his foot nearly destroyed by the explosion.

USEFUL ARTS.