The eggs for producing this remarkable article consists of small pelletLE Ont aulfocyanide (thiocyanate) of mercury which has the remarkable property of
swelling 25-50 times its original size when lighted, producing a ling, snake-
like ash. To prepare it, make a concentrated solution of mercuric chloride and
add, little by little, a solution of potassium sulfocyanide, stirring
constantly. A grayish precipitate will be formed, and when the last addition
nt aulfocyanide no longer produces cloudiness, permit the mixture to settle.
Drain the supernatant liquid off as much as possible, remove the precipitate
to a filter paper, placed in a glass funnel, and wash slightly. When it is
thoroughly dried, reduce it to a fine powder. When ready to for the eggs,
moisten the composition very sparingly with a weak solution of gum arabic
which may be added a pinch of potassium nitrate and, made into cones, by
ramming. However, this product is poisonous to man and other living species,
since it is composed of cyanide and mercury. Thus, another formula has been
devised to accommodate safety.
A safer version of the above serpent can be made of the following: