# Essays Upon The Making Of Salt-Petre And Gun-Powder/Watertown

New York Colony Committee of Safety, pages 19–22
​ [ 19 ]
ess; and whoever tries this experiment, will meet with success greatly to his satisfaction, provided his earth be good. For that purpose, take earth from under any old building (whether meeting-house, dwelling-house, barn, stable, or other building) where the earth has been long covered from the weather; dig not above six or eight inches deep, and a little experience will teach you to choose that which is loose, light and crumbly, and has a bitterish or sourish allum like taste upon the tongue; light sandy or loomy earth, such as water easily penetrates, works the kindest. Fill your leech-tubs with those earths, observing to run all your liquor through three leeches one after another, before you bale it, pouring water on to the second and the third leeches, until all the Nitre is extracted, which you must judge by the taste. When you have collected a sufficient quantity of the liquor for boiling, you must also have in readiness a quantity of common lye drawn from a bushel of ashes; mix these two liquors together (in a proper vessel) in the proportion of three parts of the former to one of the latter, and you will immediately perceive a turbidness to arise, and the liquor to look like new beer; let it stand quiet for a few hours, and an earthy sediment will settle to the bottom, leaving the liquor clear; remove this liquor (carefully from the sediment) into your kettle, either by drawing it off at a tap three or four inches from the bottom of your settling-tub, or by carefully dipping it off as you please; boil down this liquor until you find (by setting it a little in a cool place) it shoots pretty ​ [ 20 ] full of crystals, then dip it out into a tub, let it stand one or two hours to settle, then pour it off into wooden trays previously wet with cold water, and set them in a cool place, and in twenty-four hours you may pour off the liquor from the crystals; the liquor you pour off (called the mother of Salt-petre) you may either boil down again until it will crystalize, or (which is less trouble) you may mix it with your next liquor while it is setting; if you have a mind for a large crop from one boiling, you may continue to fill the kettle you intend to boil off in, with hot liquor from your other kettle, and that with cold liquor from your settling tub, until you think proper to bail off; observing all other directions as above; except you observe the colour to look of a darkish colour, in that case dip it out into your settling tub, and after a proper time pour it off from the sedimentts into your kettle, and boil it down, and crystalize, as above. It was in this way that I made fifty weight in five days. If you carefully observe the foregoing directions, your first crystals will be so clean, that (for further clarifying) they will only to be put into a clean kettle, cover them about two inches with pure water, raise the heat until they are dissolved, remove them from the fire, let them stand about fifteen minutes to settle, pour it again into your coolers, and set it aside, when it will again shoot into crystals; the liquor you pour off you may boil down and crystalize again and again, until all the water is evaporated. This method of clarifying Salt-petre is very easy, and if you find once doing it not sufficient to render your Salt-petre pure, you may ​ [ 21 ] peat it as often as you please, and your Salt-petre will lose nothing but its filth: and I think this method preferable to that hazardous one of fluxing the Salt-petre with a vehement fire. I have met with several gentlemen who object to the foregoing method on account of the large proportion of alkaline lye made use of. Supposing that the Salt-petre thus produced, may contain so much of the alkaline salt as to render it unfit for the important purpose for which it is designed. Therefore least this opinion should so far prevail as to prevent people from entering fully into the practice of this successful method, let it be observed, that Nitre (properly so called) is a spirituous fluid matter, and never will become solid till it is fixed to and blended with some solid substance, which must serve it as a basis and become the cause of its solidity; and when it is imbibed by the above earths, it adheres to and becomes intimately blended with certain particles which are called its terrene basis; and the only secret in making Salt-petre from these earths consists in separating from the Nitre this terrene basis, and in furnishing it with a vegetable alkaline basis, and thus is formed that neutral salt, called Salt-petre, This preparation and addition is performed by mixing the two lyes as abovementioned, upon mixing the two lyes as abovementioned, upon which mixing, the Nitre (having a greater fondness for the alkaline salts than for its former earthy basis) instantaneously forsakes its terrene basis, and units with the alkaline salts, and this earthy matter (being thus forsaken of the nitre) subsides to the bottom of the vessel, in form of a light earthy ​ [ 22 ] substance; and when this separation is thus performed, there is nothing more needful but to concentrate the Nitre by evaporating the water to a proper degree (and without the least difficulty) the whole of the Nitre will shot into salt-petre crystals, provided the lye had sufficiently furnished it with an alkaline basis, for it is absolutely certain that the Nitre will forsake its terrene basis, and form into Salt-petre as far as it finds this alkaline basis to form upon, and no further, and the want of a sufficient quantity of these alkaline salts, has been the sole reason why great numbers of persons have either not been able to reduce their liquor to crystals at all, or else their crystals would have been small in quantity and very foul; therefore if your Nitre lye be very strong you may add one third ash lye instead of one quarter, should the proportion be a little overplus it will not in the least injury your Salt-petre.
WILLIAM WHITING, Chairman Of the Salt-petre Committee.
In the House of Representatives, Dec. 27, 1775, read and accepted, and ordered that Dr. Whiting see that the same be printed in the several newspapers. Attest SAMUEL FREEMAN, Clerk.