A course of chemistry containing an easie method of preparing those chymical medicins which are used in physick : with curious remarks and useful discourses upon each preparation, for the benefit of such who desire to be instructed in the knowledge of this art / by Nicholas Lemery, M.D.

Distillation of Gumm Ammoniack.

This is a separation of the Oil and Spirit of Gumm Ammoniack from its earthy part.

Put a pound of Gumm Ammoniack into an earthen Retort, or glass one luted, great enough for two thirds to remain empty; place this Re∣tort in a Reverberatory Furnace, and fitting to it a Receiver, begin the distillation with a very little fire to warm gently the Retort, and drive forth drop by drop a little Phlegmatick water. When the vapours begin to appear, throw out that which is in the Receiver, and refitting it, and luting close the joints, encrease the fire by degrees, and continue it until all is come forth. Then let the vessels cool, and unlute them; pour out that which is in the Receiver into a Tunnel lined with brown paper, the Spirit will pass through, and leave the thick black Oil in the filter, keep it in a Viol: it is good for the Palsie, and Hysterical diseases: the diseased parts are rub'd with it, and it is given to women to smell to.

Put the Spirit into a glass Alembeck, and Recti∣fie it by distilling it in Sand. 'Tis a good Remedy

against the Plague, and all sorts of malignant dis∣eases; it is used in the Scurvy, and all manner of Obstructions, the dose is from eight to sixteen drops in some proper liquor.

The Spirit of all other Gumms may be drawn after the same manner.

Remarks.

Two thirds of the Retort must remain empty, because the Gumm rarifies exceedingly as it heats, and would be apt to come forth in substance, if it had not room enough. There is no need of ad∣ding alkali's for the Rectification of this Spirit, as many Authors would perswade us; this circum∣stance doth rather more hurt than good, because alkalies do spoil these sorts of Spirits, as I have said when I treated of the Rectification of the Spi∣rit of Tartar.

The phlegm is taken out of the receiver before the Spirits come forth, in order to their being the purer. You will have six drachms of phlegm, three ounces and seven drachms of Spirit, six ounces of a black & stinking oil, and there remains in the retort four ounces six drachms of a black, light and very spongious matter, which is to be flung away. It is likewise a little inflammable by reason of fuliginosi∣ties which have fallen upon it. And this is that which gave it the black colour; a great deal of the ashes of this matter is requisite to make a little salt, for the salt of Gumms being commonly more volatile than fixed, it comes forth almost all of it in acid Spirit.