The passage of incendiary compositions into gunpowder is still involved in much obscurity. Messrs Reinaud and Favé consider that a treatise, printed at Paris A.D. 1561, entitled _Livre de Cannonerie_, throws much light on the subject--"_vient de l'éclairer d'une lumière nouvelle_;" but we cannot at all agree with them in this view, and for the simple reason, that neither the names of the authors of the receipts contained in it, nor the dates, nor the countries, are given. Without either of these data, our readers, we think, will find it difficult to conceive that much new light can be thrown on the subject. The treatise contains a number of receipts for mixtures of oils, bitumens, sulphur, and nitre; and, as appears to us, all the aid given by this work towards elucidating the subject is, that these receipts are analogous to those of Marcus and of the Arabs, and have some internal evidence of having been written or copied from writings of an early date, though probably subsequent to Marcus; and, secondly the term Greek fire (_feu Grégeois_) being employed, and receipts for it given, would lead to the inference that the compositions here used under the same title were analogous to those which originally constituted the Greek fire. It is, however, certainly open to the remark, that Greek fire having become, in a great measure, a generic name for violent incendiary compositions, the term may have been applied to compositions analogous in their effects, though of more recent discovery. When, however, we find, in various distinct quarters, similar receipts; when we find these appearing at different epochs, and having different degrees of approximation to the explosive compounds which a more matured experience has rendered certain in their composition, the discovery of such a book as this becomes certainly a corroborative circumstance in favour of that view which regards the Greek fire as never having become extinct, and as having, by progressive but unequal gradations, changed into gunpowder. In discussing the treatise above mentioned, there is a naïve expression of our authors, who, in remarking the necessary slow combustion of these compounds from the imperfections of the processes of manufacturing saltpetre, also given in the same book, say:--"One sees how much there is that is providential in the progress of human invention. If man had, in the first instance, a powder as strong as at present, he would probably have been unable to master this force, or to use it with suitable instruments, and the discovery would have remained without application. We see that, thanks to the primitive impurity of the saltpetre, man employed mixtures of it with sulphur and charcoal, which produced a force suitable for throwing to short distances feeble parcels of incendiary matter. This force increased little by little, as men became better able to refine saltpetre, and ends by enabling them to employ it for throwing projectiles."