Apparent objections to the Glacial Theory. 307 



exist, because it seems to be well proved, that such glaciers have 

 formerly descended to far greater distances over the lower lands than 

 they do now, and undoubtedly the deposition of many of the blocks 

 observed at considerable distances from the limit of the present Al- 

 pine glaciers, is due to the agency of ice. What I would insist 

 upon is, that the numerous boulders termed erratic blocks which 

 lie scattered abroad over the countries of the north, and even in 

 our own Island, where no glaciers exist, are not due to the agency 

 of glaciers, but to that of the powerful rush of retreating waters, 

 as the lands of the northern Hemisphere arose from out the ocean, 

 with which they were formerly covered. 

 Mussooree, \th March, 1844. 



On a method of treating Mineral Sulphurets, especially 

 those of Copper, for the manufacture of Sulphuric Acid, 

 and the extraction of their Metallic Base. By Lieut, 

 Thomas Latter, 67th Regiment Bengal Native Infantry. 

 Plate xxiii. 



The following method of treating mineral sulphurets, es- 

 pecially those of copper, having been for some time employ- 

 ed with great success in France, and on account of its sim- 

 plicity and cheapness, being peculiarly adapted for use 

 among the natives of India, I take an early opportunity of 

 publishing it through the medium of your Journal. 



It may be necessary to premise, that this method employed 

 in Lyons for the treatment of sulphurets of copper, was for 

 the primary purpose of manufacturing sulphuric acid, after 

 which, the remaining metallic slag was treated for the cop- 

 per that it might contain, and ores which were found to yield 

 not more than 1| per cent, of metal, were thus treated with 

 profit. 



The ores are placed in furnaces of a peculiar shape, 

 having around head, with a narrow neck, fig. 1, front-view ; 



