SALTPETRE, or Niter: is a Nitrate of Potassium. It is the principal ingredient in gunpowder and has various other industrial as well as medicinal uses. It is valuable in meat preserving, as the use of small quantities in the curing of hams, bacon, corned beef, sausages, etc., imparts or retains an attractive red color. The principal importations are from India, where the crude product is secured, as in other Eastern countries, by lixiviation of the earth containing it. It is also made artificially by treatment of the nitrates resulting from the mixture of animal refuse, etc., with quicklime.