144 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VoL. I. 



quantities. It is the best known law of Hydrostatics that a fluid will 

 flow until it finds its level ; but pour water on any highly heated surface 

 and instead of flowing until it finds its level and keeping in a body, it 

 will break up into little globules and either roll about or stand still, until 

 the atmosperc in its vicinity is cooled sufficiently, when it evaporates in 

 steam. 



The same may be said of the metals with a little modification, the sur- 

 face will do as well if it is cold, and not so well if it is at too high a 

 temperature, unless there be a good supply of cold air playing on the 

 surface ; but it all depends on the melting point of the metal and the 

 rapidity with which it cools. On studying this I have come to the con- 

 clusion, that the heat radiated from the metal or alloy heats the air in 

 its vicinity, that by the law of gravitation, the heated air having expanded 

 and thus having a lower density than the cold air, ascends to make room 

 for the same, that the rapidity with which it ascends partly breaks the 

 equilibrium of the atmospheric pressure, that the pressure being less on 

 the upper surface it is inclined to rise and thus partly kept from spreading 

 or finding its level, that it is aided in this by a lateral pressure, if I may 

 :so express it, which is not disturbed by the ascension of the heated 

 air. That this is true may be seen by a great many metals when 

 cooled suddenly by artificial means, or not formed into globules until 

 on the point of solidifying, they will be seen to have their tops (the 

 globules) very much flattened ; this shows at once that it is the exertion 

 of the atmospheric pressure, as if they had been hot or not cooled so 

 suddenly, their tops would not have been flattened. 



Why then could these laws not be applied in the metallurgical treat- 

 ment of our gold and silver ores ? The sulphur and arsenic would assist 

 to lower the temperature at which they melt, by alloying with them and 

 any portion that did not combine with them would act as a flux. I need 

 not extol the virtues of such a flux, it would collect any fine gold and 

 bring it in conjunction with more, forming a globule, while at the same 

 time the sulphur would act as fuel and produce heat, the arsenic according 

 to its nature would cause any body of metal it happened to be in to 

 shrink and form a globule, thus all the fine and leaf gold would be col- 

 lected into bodies large enough to be easily worked, and this could be 

 done by roasting, but not roasting as is practised at the present day, as 

 arsenic and sulphur are considered a disadvantage and it is to get rid of 

 them that it is practised. Allow me to quote a passage from Overman, 

 the late American metallurgist, as it will show us the object of roasting 

 as it exists ; he says, " Roasting means to heat a metallic ore or matte to 

 at least a red heat or such a heat that the mineral does not melt but only 



