The Third Part of the Prosperity of Germany

in the saltpeter, we ought to demolish the entire vault and reduce it to a very fine powder with the help of a mill. Warm water must be poured onto the powder so that the lye may be extracted from it. This, diminished by convenient evaporation, must be placed in a cold location for crystallizing. This artifice of cooking and crystallization will be explained at the end of this work with appropriate figures. But if we have seen that the salt extracted from those particles of the vault does not yet catch flame, let it be an indication to us that it has not yet been sufficiently animated by the air. For air gives life, which fire strongly attracts, such that with the help of fire, air and life are enticed, from which the salt is animated and becomes flammable. Fire therefore comes to be administered here again, and the vault must be rendered constantly humid with rainwater. It is better, if it can be had, to use that rainwater which falls by the help of the north wind, although if rainwater is lacking, water of another condition can be substituted in its place. This pouring of water must be continued for so long, always allowing the vault to be properly dried before new water is sprinkled on, until the salt clinging in the vault, by the benefit of fire and air, has been found to be sufficiently animated and flammable when you have performed the test by the stated method.

This is the concise way of preparing a good quantity of saltpeter, solely through lime, wood ashes, and the urine of man or