322 Mr. W. Herapath's Contributions 



taking it must be long before it will be complete. In the mean 

 time I shall produce evidence enough to show what I con- 

 ceive to be general laws, leaving it to futurity to give them 

 absolute precision. 



As a basis, I have taken, as accurately as I could, the den- 

 sities arranged below : some few are of no value to this in- 

 quiry ; but as they may be serviceable to others, I shall give 

 the whole list : 



Cadmium, perfectly pure 62° 8*659 



Cadmium, brown oxide 62 8*183 



Cadmium, carbonate, dried at 180° ... 63 4*420 



Copper, not poled 65 8*510 



The same copper, poled 64 8*843 



Copper, in grains 64 8*6006 



Copper, pure, melted, and cooled in crucible 62 8*900 

 Copper, red oxide, as made from acetate . 62 6*093 

 Copper, red oxide, by heating copper . . 62 6*052 

 Copper, black oxide, from heating with nitre 62 6*401 



Copper, sulphuret 64 5*792 



Tin of commerce, containing lead ... 64 7*602 



Tin, hammered 64 7*600 



Tin, remelted, and allowed to cool in crucible 64 7*5565 

 Tin, pure, as reduced from white oxide, 1 fi2 7-9ft-; 



hammered the same . -. . . / 



Tin, gray oxide, from muriatic acid, by potash 62 6*666 



Tin, white oxide 64 4*933 



Tin, white oxide, heated till yellow ... 62 6*639 



Lead, pure 62 11*352 



Lead, yellow oxide 64 9*277 



Lead, red oxide 60 9*096 



Lead, puce-coloured oxide 62 8*902 



Arsenic, pure (metallic) 62 5*672 



Arsenious acid, glacial 63 3*729 



Bismuth 61 9*831 



Bismuth, white oxide 62 6*7608 



Bismuth, white oxide, heated till yellow . 65 8*211 



Bismuth, sulphuret 58 7*591 



Iron, black oxide, as produced in oxygen gas 62 5*300 

 Iron, red oxide, from nitric acid .... 62 4*959 



Mercury, black oxide 62 10*69 



Mercury, red, from nitric acid 64 1 1 *074 



Mercury, red oxide (per se) 65 11*085 



Mercury, proto-chloride (calomel) ... 60 6*707 



Silver, brown oxide 62 7*143 



Silver, chloride 66 5*129 



Manganese 



