1868. J MACFARLANE — EXTRACTION OF COPPER. 457 



Among the oaks, Querents castuncefolia, Q. ambigua, Q. 

 aquatica and Q. haliphlceos were fine foliaged kinds. 



M. Rissot, Inspector of the Forests of the Bois de 

 Boulogne, exhibited a good collection of conifers, more suit- 

 able in general for forest planting ; among which were some 

 Mexican species of Pinus, which seemed hardy looking kinds. 

 The same exhibitor had also a good general collection of forest 

 trees. 



A series of plants were also exhibited for the purpose of 

 showing the effects of prunning by different methods, prepara- 

 tory to planting in forests and in towns, as well as for 

 ordinary ornamental purposes. This was not a successful exhibition, 

 as many, in fact nearly all, the trees which had been brought for 

 the purpose were dead, owing to their having been removed at a 

 late period of the year. 



ON THE EXTRACTION OF COPPER FROM ITS ORES 

 IN THE HUMID WAY. 



By Thomas Macfarlane. 



In a former paper on this subject published some time ago in 

 this Journal,* I described a series of experiments, which had, 

 for their object, the economical extraction of the copper 

 contained in the poor pyritous ores of the Eastern Town- 

 ships. The results of these experiments may be briefly stated 

 here. It was shewn — 1st, That it is impossible to remove 

 from a very pyritous ore, by simple calcination with com- 

 mon salt, and lixiviation with water, more than a small propor- 

 tion of its copper contents; 2nd, That by calcining such an ore 

 with twice its weight of impure iron oxide, and the necessary 

 quantity of common salt, it is possible to remove 95 per cent, of 

 the copper; 3rd, That, if, in such an operation, a temperature 

 much above redness be employed, copper is, to a considerable 

 extent, volatilized ; 4th, That in order to complete extraction it 

 is necessary that the materials should remain undisturbed during 

 calcination ; 5th, That even with the use of a large quantity of 

 iron oxide and salt, it is impossible to extract the whole of the 



* Yol. ii [2nd series], p. 219. 



