between the old Scandinavian and British armourer to teach them the most useful combinations of the new alloy. If the sword or spear proved either too ductile or too brittle for use, it would be consigned anew to the furnace, with such additions to the mixed metals as experience must soon suggest. The same would hold good even if we suppose that, as Cæsar affirms, the Britons used imported bronze, (_ære utuntur importato_.) Whether the tin and copper were mixed by Phœnician, Roman, or British metallurgists, similar proportional combinations of the two would necessarily be the result of experience. It will be seen, however, that the "Celtic brass" of British archæologists is neither invariably composed of exactly the same proportions of tin and copper, nor even solely of these two metals. One of the most elaborate and valuable reports published on this subject is contained in a communication read to the Royal Society of London, June 9, 1796, and printed in the Philosophical Transactions of that year. It is entitled, "Observations on some metallic arms and utensils, with experiments to determine their composition," by George Pearson, M.D., F.R.S. His experiments were both analytic and synthetic, and consequently enable us to trace the probable experience of the primitive metallurgist, before he had ascertained the most useful proportions of the metals for practical purposes. Copper, we know, is not unfrequently found native in its metallic state, and fit for immediate use. Tin, though never found in this state, occurs in England in the same locality with the copper, and often near the surface. It might, therefore, even accidentally be combined with the former metal. The fact of the two possessing, when in combination, the requisite hardness for domestic or warlike purposes which neither of them has when alone, appears to have been ascertained at a very remote period. In addition to this indispensable property, the combination possesses the valuable qualities of being more readily fusible and continuing longer in the fluid state. Hence the mixture of two of the metals most readily accessible to the native Briton greatly facilitated all his other operations.