146 TRANSACTIONS OF TIIIC CANADIAN INSTITUTE. [VoL. T. 



the work of cleansing left to the buddies, but the wet way is to be 

 recommended as it will save a great deal of work in the buddies ; the 

 battery may be cleaned out every hour or a less period of time, accord- 

 ing to the amount of ore that has accumulated in it, and carried to the 

 round buddies to be selected. All the gold and silver will be left in the 

 battery, except, perhaps, those fine shots which may be ejected by the 

 stroke of the stamps, and which will be intercepted by the hardwood 

 riffles ; as for the tailings, they will be found to contain practically 

 nothing. 



Naturally you will have come to the conclusion that the arsenic and 

 sulphur which were alloyed with the gold and silver, will still remain with 

 them and be troublesome impurities, which can only be got rid of by 

 refining, thus causing a further outlay of time and capital. This will 

 depend principally on the temperature to which the ore has been exposed. 

 If the temperature is only risen to that point at which the gold and silver 

 melt, they certainly will contain these elements as an alloy, but if on the 

 other hand, they are risen to that temperature which is obtainable in any 

 roast pile, the gold and silver will be found free of even traces of these 

 elements. In proof of this I shall make mention of an experiment by 

 which I demonstrated it. I took ore known to contain both arsenic and 

 sulphur and divided it into two portions, which we shall call A and B. I 

 raised A in temperature until the gold was seen to form on the surface in 

 globules and no higher. B I raised in tem.perature until it sintered. I 

 afterwards made analysis of several of the globules from each portion ; 

 in A I found both arsenic and sulphur, and in further proof of my state- 

 ment that arsenic and gold alloy, I found it (the arsenic) in the metallic 

 state. I do believe that this could not have been confirmed more conclu- 

 sively than by the finding of the metallic arsenic present. In the several 

 globules from B, I found neither arsenic nor sulphur, thus shewing that 

 the high temperature to which the ore had been exposed had oxidized 

 them. 



The oxidization is accomplished as follows : the extreme heat of the 

 roast pile, when sintering, sets the sulphur and arsenic on fire, producing 

 arsenical and sulphur fumes ; the arsenical fumes combine with the' oxy- 

 gen of the air forming arsenious acid, As.Os, of the old nomenclature, or 

 arsenious anhydride of the new, Aso.Os, and with the sulphur as sulphur 

 dioxide, or sulphurous anhydride S.Oj, and also combine together to form 

 the sulphides, the orange realgar As.Si, and the yellow orpiment As.Ss. 

 I found the former predominated. Also when the water is thrown on 

 the ore it helps greatly the oxidization of these elements, and clears 

 away almost all traces of them. 



