It is said to be doubted whether Albertus was the author of the book which bears his name; but that he, whoever he may have been, and Bacon, are presumed to have taken their information from the same identical source. About the period of the invention of gunpowder, it appears the art of making the Greek fire began to be lost. In the works of Roger Bacon, the term occurs three times. According to Casiri, the term _pulvis nitratus_, is to be found in an Arabic MS. the author of which existed about 1249. If the work of Geber, _De Investigatione Perfectionis_, be genuine, and if this writer lived, as has been thought, in the eighth century, it would be the oldest where saltpetre is mentioned, in a prescription for an _aqua solutiva_, which appears to be almost _aqua regia_. We are inclined to believe, however, from various authorities, that gunpowder was invented in India, as it was proved in a paper read before the French National Institute, by M. Langles, that the Arabians obtained a knowledge of gunpowder from the Indians, who had been acquainted with it from the earliest periods. The use of it in war is said to have been prohibited them in their sacred books. It was employed in 690 at a battle near Mecca, by the Arabians. It was brought by the Saracens from Africa to the Europeans, who improved the preparation, and first discovered various ways of employing it in war. In no country could saltpetre and its various uses be more easily discovered than in India, where the soil is so rich in nitrous particles that nothing is necessary but lixiviation to obtain saltpetre; and where this substance is so abundant, that almost all the gunpowder used in different wars, with which European sovereigns have tormented themselves, burdened their subjects with intolerable taxes, and cursed the world from its invention--has been made from Indian saltpetre. Had not saltpetre been known previous to the thirteenth century, neither could gunpowder or aquafortis have existed; and for the best of all reasons, that neither of them could be made without saltpetre or nitre. But should it appear that this neutral salt was known in India long prior to that period, and used by Indians as well as Arabians before they were employed by Europeans, and considering the former to have practised chemistry previous to the latter; should this have been proved, perhaps a similar proof will necessarily await upon the articles aquafortis and gunpowder. Because if this affirmation be established, it will be discovered that Europeans knew nothing of aquafortis until after the Arabian chemists. Probability appears to favour the idea, that at or about the twelfth century the accumulated number of consequents, from the improvement in European science, the arts we now possess were introduced into our catalogue, _i. e._, nitre, aquafortis, and gunpowder.