116 Mr. W. H. Keiiting on the Cadmia found at 



it was found in tabular masses, presenting in many cases a 

 distinct slaty structure. The substance has often a striped 

 aspect; its colour is grayish, inclining to yellow, green or 

 black. The specific gravity of the European is 5-25, of the 

 American 4*92 ; this difference is not very great, and may in 

 part be accounted for, by the foct that the former contains a 

 small quantity of lead, which varies from 2-4' to 6*0 per lOO'O. 



The chemical analysis of this substance made in New- York, 

 has rendered it unnecessary for me to undertake that which I 

 proposed makuig. I shall merely add a comparative view of 

 the results of the analyses, made upon the European and 

 American. 



Bouesnel. Drappier. Berthier. Torrey. 



Oxide of zinc 90-1 9-i-O 87-0 , 93-5 



lead 6-0 2*4 4.-9 



iron 1-6 2-6 3-6 3*5 



Carbon I'O 0-5 0*6 1*0 



Silex, earths, sand, &c. 1*8 3*4 



100-5 99-5 99-5 98-0 



These analyses present a remarkable coincidence, except in 

 the presence of lead in the European, and its absence in the 

 American cadmia ; but this diffei'ence is of no importance ; in 

 Belgium Mr. Bouesnel tells us that the iron ore is visibly in- 

 termixed with lead ore, and this accounts for its existence in 

 the cadmia ; we are also told that lead is found there in the 

 furnaces below the metallic iron. It is not difficult to account 

 for the presence of zinc with the iron ore ; for in examining the 

 ore bed at Salisbury ( 1 1 miles east of the furnace) we ascer- 

 tained that the hematite was found in the side of a hill, incum- 

 bent upon the schist, and, as it were, incased in the decomposed 

 part of it, and that the adjoining schist was very much broken 

 up and altered : it does not appear that the hematite is the re- 

 sult of infiltration alone, for masses of micaceous iron ore are 

 found connected with it, which appear to indicate that it re- 

 sults, in part at least, from the decomposition of oxidule or 

 oligist iron ore. We know that this schist contains blende or 

 sulphuret of zinc, in some places at least, as at the Ancram 

 lead-works, and this may account for the presence of zinc. 



Mr. Bouesnel has endeavoured to explain the formation of 

 these cadmia, in a manner which does not appear to me to be 

 satisfactory. I would rather admit that it results from a reduc- 

 tion of the oxide or carbonate of zinc, which is intermixed in 

 small quantities widi the iron ore ; that this reduction takes 

 place in tlie furnace ; that the zinc sublimes and oxidates as it 

 rises, and settles in the form of a ring at the infei'ior jnirt of 



the 



