CHAP. XXIX.

_A philosophical Mushroom._

Among the numerous and surprising phenomenons produced by different

chymical proceedings, one of the most curious is certainly that of the

inflammation of essential oils, by the mixture of nitrous acid. It

is certainly astonishing to see a cold liquor take fire on pouring

another cold liquor on it; such are the means by which one may form in

three minutes the mushroom, called the philosophical mushroom.

In order to make this extraordinary and entertaining experiment, you

must provide yourself with a glass, having a large foot, the basis of

this glass is to terminate in a point, as the annexed figure shews.

[Illustration]

Put in the glass an ounce of spirits of nitre, well rarified; then

pour over it an ounce of essential oil of guaiacum. This mixture will

produce a very considerable ferment, attended with smoak, out of

which there will rise, in the space of three minutes, a spungy body,

resembling perfectly a common mushroom.

This spungy substance, formed by the fat and oily particles of the

guaiacum wood, being drawn up by the air, covers itself with a very

thin coat of the matter that composes the oil of guaiacum.

Physical Amusements and Diverting Experiments Composed and Performed in Different Capitals of Europe, and in London · 第 42 / 54 题