All these discoveries belong to different periods. ~Mr. Duten’s account.~ Mr. Dutens carried the antiquity of gunpowder very high; and refers to the accounts given by Virgil, and others, of Salmonens’ attempt to imitate thunder, presuming from hence that he used a composition of the nature of Gunpowder. ~Known in China, A. D. 85.~ It has been said that it was used in China as early as the year A. D. 85, and that the knowledge of it was conveyed to us from the Arabs, on the return of the Crusaders to Europe. ~Known in India, A. D. 250.~ The Brahmas and Indians, whose practice is recorded by Philostratus, in his life of Appolonius Tyanœus, written about 1600 years ago. “These truly wise men,” says he, “dwell between the rivers Hyphasis and Ganges; their country Alexander never entered, their cities he never could have taken, for they come not out to the field to fight those who attack them, but they overthrow their enemies with tempests and thunderbolts, shot from their walls.” This is a most striking illustration of the antiquity of Gunpowder, for if some such composition be not implied in the foregoing quotation, it must remain for ever perfectly unintelligible. Saltpetre, which is the principal ingredient of Gunpowder, is found in its natural state in the East, and from this it seems highly probable they were acquainted with the composition of Gunpowder before the Europeans. ~Powder at siege of Mecca, A. D. 690.~ The Arabs are said to have employed Gunpowder at the siege of Mecca, A. D. 690. ~Oldest book on gunpowder A. D. 900.~ There is a manuscript book still extant, entitled Liber Ignium, written by Marcus Græcus, who lived about the end of the eighth century, and the composition there prescribed is 6lbs. saltpetre, 2lbs. charcoal, 1lb. sulphur, to be well powdered and mixed in a stone mortar. ~Work on gunpowder in Escurial Collection A. D. 1249.~ There is in the Escurial Collection a treatise on Gunpowder, written in 1249. ~Roger Bacon on powder, A. D. 1267.~ Our countryman, Roger Bacon, who was born 1214, and published works at Oxford 1267, expressly mentions the ingredients of Gunpowder, not as any new discovery, but as a well known composition, used for recreation. He describes it as producing a noise like thunder, and flashes like lightning, but more terrible than those produced by nature; and adds that it might be applied to the destruction of an army or a city. Bacon, in his treatise “De Secretis Operibus,” says that from saltpetre, sulphur, and wood coals, we are able to make a fire that shall burn at any distance we please. ~Tradition of Schwartz, A. D. 1320.~ ~Mortar.~