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Avithout hopes that something may yet be done in a similar direc- 

 tion with ores far less rich than those of Mount Morgan. In 

 cases where the pyrites contain small percentages of copper it is 

 possible sometimes to extract this economically by the wet pro- 

 cess by the aid of sulphuric acid. There are many other possible 

 ways in which the acid might be utilised, but the success of any 

 one of them would depend largely on local circumstances. We 

 have heard something lately of so-called j)aint mines. By these 

 are meant of course deposits of coloured oxides of iron which can 

 be manufactured into paints. At Ballarat the residues after 

 roasting iron pyrites and extraction of the gold are now being- 

 utilised for this purpose, the oxide of iron being in a very fine 

 state of division and of sufficiently good colour to command a 

 sale. Reference has been made to the preparation of chlorine for 

 the extraction of gold. In the chlorination process chloride of 

 lime is used as the source of chlorine. Now this substance in 

 solution is generally regarded as a mixture of calcium chloride 

 and hypochlorite, but whatever view be held as to its nature, less 

 than half its weight is chlorine available for the purpose of gold 

 extraction. Is it not somewhat anomalous that the chlorine 

 should first have to be prepared in Europe, then converted into 

 chloride of lime, of which remember less than half the weight is 

 chlorine, then imported to Australia, with very often a consider- 

 able loss of chlorine before it is actually used. It will perhaps 

 be said that all this is compensated for by convenience in working- 

 and saving of time and labour where this substance is used, the 

 direct use of chlorine involving extra plant, and perhaps more wear 

 and tear. Be this as it may, there still seems to me to be matter 

 for reflection for those concerned. A suggestion has been made 

 to use bromine water instead of chlorine gas, the bromine 

 being of course all recovered and used again. The obstacle here 

 would be the shipping difficulty, bromine being a dangerous sub- 

 stance to deal with if a breakage should occur. In appliances for 

 gold-saving by amalgamation the necessity for bringing the mer- 

 cury into intimate contact with the finely divided gold is becoming 

 more and more apparent. Attempts have been made with more 

 or less success to effect this by means of grinding machinery, but 

 lately a process has been patented which presents some new fea- 

 tures. The roasted auriferous ore in a fine state of division is 

 brought by means of a powerful blast in contact with the vapour 

 of boiling mercury. It is claimed that by this means a very per- 

 fect amalgamation takes place, the mercury condensing and 

 taking the gold down with it. It is claimed that the process can 

 be made continuous by using the same mercury over again. It 

 is an ingenious idea, but one of the difficulties, it seems to me, 

 will be the loss of mercury by oxidation, caused by contact of the 



