1. _Iron with tin._ These two metals are alloyed with some difficulty by fusion in a close crucible. The difficulty seems to arise from the very unequal temperatures at which the metals individually fuse. Bergman always found two alloys when the metals were fused together; the one composed of 21 parts tin and 1 of iron, that is, 10 atoms of tin to 1 of iron; and the other of 2 parts iron, and 1 of tin; that is, 4 atoms of iron and 1 of tin. The first was very malleable, harder than tin and not so brilliant; the second but moderately malleable and too hard to yield to the knife. The formation of common _tin-plate_ is a proof of the affinity of tin and iron. Thin plates of iron, thoroughly cleaned, are dipped into melted tin, when the tin adheres to the surface of the iron, forming with that metal a true chemical union. 2. _Iron and lead_, &c. Iron combines by fusion more or less perfectly with lead, zinc, bismuth, antimony, arsenic, cobalt, manganese, &c. but the proportions have in few instances been ascertained, and the compounds are generally of little importance. _Alloys of Nickel and other Metals._ _Nickel and arsenic._ As nickel and arsenic are naturally found in combination, though mostly along with small quantities of other bodies, it is to be presumed that an affinity subsists between them; but I do not know that the proportions have been ascertained in which they unite, or the nature of the alloys. _Alloys of Tin with other Metals._ 1. _Tin with lead._ Tin and lead unite by fusion in any proportion. This alloy, according to Muschenbroek, is harder and much more tenacious than either tin or lead, especially when 3 parts tin and 1 lead are its constituents. I fused various proportions of tin and lead together, as per the following table, in order to find some of the more prominent characteristics of the several alloys. The specific gravity of the tin was 7.2, that of the lead was 11.23; and the portions taken were such as to combine, 1, 2, or more atoms of tin with 1 of lead. The several metals were melted and the compounds formed under a few drops of tallow, otherwise the oxidation is so rapid that the proportions are disturbed and the quantity of pure alloy is not equal to the weight of the ingredients. Without this precaution it is no uncommon occurrence in small experiments to obtain only 3 parts of fusible alloy from 4 of metal. Atoms. | Weights | Sp. Gr. by | Sp Gr. by | Fusing | |calculation.| experim. | Point. Tin. Lead. | Tin. Lead. | | | 1 + 1 | .58 + 1 | 9.32 | 9.17 | 430° 2 + 1 | 1.16 + 1 | 8.64 | 8.79 | 350 3 + 1 | 1.73 + 1 | 8.25 | 8.49 | 340 4 + 1 | 2.3 + 1 | 8.00 | 8.10 | 345 5 + 1 | 2.9 + 1 | 7.93 | 8.00 | 350 6 + 1 | 3.47 + 1 | 7.81 | 7.90 | 360