44 PHILOSOPHICAL TRANSACTIONS. [ANNO I796. 



(e) The white sediment (c) was a light impalpably fine powder: it had a little 

 metallic tarte: it could not be melted with borax by flame with the blow-pipe, but 

 was diffused through that salt, and rendered it opaque. This sediment dissolved 

 totally, except a little mere dirt, by long digestion in muriatic acid, and imme- 

 diately in this menstruum when caloric was applied to make it boil. This solution 

 in muriatic acid did not throw down Cassius' precipitate on adding to it nitro- 

 muriate of gold, but afforded a white deposit exactly like that which is made on 

 adding nitro-muriate of gold to muriate of tin, made either by boiling tin in a large 

 proportion of muriatic acid, or by dissolving oxyde of tin, made with nitric acid, 

 in muriatic acid. The muriatic solution of the white sediment (c,) on adding 

 prussiate of soda, afforded a precipitate exactly like that which appears on adding 

 prussiate of soda to muriate of tin. 



The white sediment (c) being mixed with tartar, on charcoal, the flame of a 

 candle by the blow-pipe was directed upon it: by which treatment small silver-like 

 globules were made to appear. These globules being collected, were digested in 

 the cold, in so small a proportion of muriatic acid as could not dissolve the whole 

 of the globules supposing them to be tin. They were gradually almost all dissolved, 

 and nitro-muriate of gold being added, Cassius' precipitate was immediately de- 

 posited. But the metallic globules being dissolved by boiling in a large proportion 

 of muriatic acid, no Cassius' precipitate was produced on adding nitro-muriate of 

 gold; nor on adding it to tin dissolved by boiling in a large quantity of mu- 

 riatic acid. 



The preceding analytical observations and experiments will, on examination, 

 perhaps be found to contain sufficient evidence to demonstrate that each of the 

 ancient metallic instruments contains copper and tin ; and they will also perhaps be 

 found to prove, that these metals contain no other kind of metal, or other species 

 of matter. But, in order to ascertain the proportion of the tin to the copper more 

 accurately than I was able to do by analysis, and also in order to confirm or inva- 

 lidate the evidence of analysis, I made the following synthetical observations and 

 experiments. 



§6. Synthetical observations and experiments. — Exper. 1. 50 grs. of tin were 

 united by fusion with 1000 grs. of copper. The ingot of this allay of 20 parts of 

 copper by 1 of tin, when polished, differed from the celt metals in shade of the 

 same colour; these being much paler than this allay. It was a good deal harder, 

 and not so tough as copper, but it was not so hard, and was more tough than the 

 celt metals. Its fracture showed also a more open grain than the old metals, and 

 more inclining to the peculiar red colour of copper, instead of the brown and grey, 

 or slate colour of the ancient metals. With nitric acid it afforded, like the ancient 

 metals, a blue liquor, and white deposit of oxyde of tin ; but in much smaller pro- 

 portion than any of them; not being more than 7 percent. 



Exper. 2. 100 grs. of tin were united by fusion with 1500 grs. of copper. This 

 allay of 15 parts of copper with 1 of tin resembled the celt metals, N° 1 and N° 2, 



