VOL. LXXXVI.] PHILOSOPHICAL TRANSACTIONS. 45 



in colour, polished surface, grain of the fracture, and brown colour of the fracture ; 

 consequently the red colour of the copper was completely destroyed. It was not 

 however so hard, though stronger than these celt metals; but was harder than the 

 spear and the sauce pan. The solution of this allay with nitric acid only differed 

 from that in the former experiment in affording a more copious white deposit, 

 namely, 10 per cent, of it in its dried state. 



Eocper. 3. 100 grs. of tin were melted with 1200 grs. of copper. This allay of 

 12 parts of copper by one of tin could scarcely be distinguished from the last de- 

 scribed allay in the colour of the polished surface, nor was it so much closer 

 grained or lighter coloured in its fracture as might have been expected ; nor could 

 I by the hammer distinguish it from that allay in point of hardness and strength. 

 On the trial with the drill, it however betrayed a good deal more hardness. It was 

 almost as hard as the celts, N° 1 and N° 2. With nitric acid it afforded a deposit 

 of 1 1 per cent, of oxyde of tin. 



Exper. 4. 100 grs. of tin were united by fusion with 1000 grs. of copper. This 

 allay of copper with -^ of its weight of tin was as pale coloured as the celts, N° ] 

 andN 2, but not nearly so pale as the celt, N°3. I could not distinguish this 

 allay in the properties of hardness and strength from the 2 celts, N° l and N° 2, 

 and the scabbard ; but it was harder than the spear-head and sauce-pan, though not 

 so brittle. Its fracture showed the same kind of rather open grain, and texture, 

 as that of the celts, N° 1 and N° 2, before they were melted, but it was not so 

 close grained as any of the ancient metals after fusion ; and it differed from all of 

 them in being of a lightish brown colour. The solution in nitric acid differed 

 only from the former in affording a greater proportion of white deposit, namely, 

 13-^ grs. per cent. 



Exper. 5. 900 grs. of copper were melted with 100 grs. of tin: which allay of 

 9 parts of copper with 1 of tin differed very little from the former. By means of 

 nitric acid this allay gave 17 grs. per cent, of oxyde of tin. 



Exper. 6. 100 grs. of tin were melted with 800 grs. of copper. This allay of 8 

 parts of copper with 1 of tin was also scarcely distinguishable from the 2 former 

 allays, in colour, strength, appearance of fracture, texture, and polish. With 

 nitric acid this allay afforded 1 84- grs. per cent, of oxyde of tin. 



Exper. 7. 100 grs. of tin were melted with 700grs. of copper. This allay of 7 

 parts of copper with 1 part of tin was evidently different from any of the former 

 allays ; being harder, more brittle, paler coloured, the fracture showing a much 

 finer grain, and of a grey or somewhat slate colour. The grain therefore of this 

 allay resembles in colour that of the celt, N° 3, the lituus, the spear-head, and 

 the scabbard. It was especially like the lituus and the celt, N° 3, in the rather 

 bright and silvery appearance of the fracture, instead of the dull slate colour of the 

 spear-head and sauce-pan. On trial with the hammer, and the drill, it resembled 

 exactly the lituus in brittieness and hardness. It was a little harder and more brittle 



