Note 1190 — SALTPETRE. GUNPOWDER. AQUAFORTIS.

To this subject belong the following works:—Ars Magna Artilleriæ, Auct. Cas. Siomienowicz. Amst. 1650, fol. p. 61. The author thinks that the nitrum of the ancients is not at present known.

Natural History of Nitre, by W. Clarke. Lond. 1670, 8vo. It is here said that the nitrum of the ancients was impure saltpetre, and that the latter is produced from the former by purification.

G. C. Schelhameri de Nitro, cum veterum, tum nostro commentatio, Amst. 1709, 8vo, contains good philological observations, particularly in regard to the period, but leaves the question undetermined.

Saggi sul ristabilimento dell’ antica arte de’ Greci e Romani pittori, del Sig. Doct. Vin. Requeno. Parma, 1787, 2 tomi in 8vo, ii. pp. 95, 131: a learned but diffuse work. He thinks that the nitrum of the ancients was our saltpetre; and what others consider as proofs of its being mineralized alkali, he understands as indicating alkalized saltpetre. I am not, however, convinced. Before I ascribe to the ancients a knowledge of our saltpetre, I must be shown in their writings properties of their nitrum sufficient to satisfy me that it was the same substance.

Commentat. de nitro Plinii, in J. D. Michaelis commentationes. Bremæ 1784, 4to. The author only illustrates the account of Pliny, and states what, according to his opinion, we are to understand in it in regard to alkali, and what in regard to our saltpetre.