In latine Sal Petrae, rather so called, because exudat è petris, it usually sweats out of rocks, then, because it is wrought up at the last to a rocky or a stony consistency. Some conceive it utterly unknown to the ancients, which learned Hoffman will not allow, onely it was disguised unto them, under the name of Sal nitrum, though our modern use was unknown unto them, that Pulvis nitrosus, or Gun-powder might be made thereof. It is 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉 what will easily take fire, the best Test of the goodness thereof.
But, why is Salt-peter (common to all Counties) insisted on in Northamptonshire? Because, most thereof is found in Dove-houses, and most Dove-houses in this great Corn County. Yet are not those Emblemes of innocency, guilty in any degree of those de∣structions, which are made by that, which is made thereof. All that I will adde of Salt-peter, is this, I have read in a learned * 1.1 Writer that Salt-peter-men, when they have extracted Salt-peter out of a floor of earth one year, within three or four years after, they find more generated there, and do work it over again.