126 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VoL. II. 



of Florida, with the difference that it is a fresh water spring. As for the 

 salts, galena is oxidized from the sulphide to the sulphate and further 

 to carbonate by atmospheric agency and surface water containing 

 carbon dioxide. In the first place the gold would exist as sulphide in 

 the galena ; on decomposition it would be converted into the terchloride 

 by chlorine, as also would the lead and silver to their respective 

 chlorides. But the enormous power of carbon dioxide, assisted by heat, 

 has been overlooked in works on chemical geology, or rather the power, 

 especially of alkaline carbonate. The carbonate of lead being soluble in 

 an alkaline carbonate would be carried along by currents until, perhaps, 

 passing where the waters of a sulphur spring emerged into the sea, or 

 lake, or perhaps the spring burst from the bed of same, these waters 

 being charged with hydrogen sulphides, that gas, or rather solution of 

 gas, would decompose the carbonate as follows : — 



Pb. CO3 + H2 S = Pb. S+H, CO3, 

 thus forming carbonic acid and sulphide of lead. Then the process 

 involved taking the hyposulphite solution as agent would be as follows : 

 The silver having been converted into chloride would be dissolved by 

 the sea or lacustrine hyposulphite solution, it was also possible for a 

 spring of fresh water, such as I have mentioned, to have existed in those 

 seas or lakes ; hence, were this solution to pass through this pillar of 

 ascending water, or at least some of it, to be mixed with this solution, 

 then the silver would be precipitated as sulphide, the reaction is as 

 follows : — 



Na,S2034-Ag.Cl. = (Na.Ag.)S,03+Na.Cl. 



(Na.Ag.)S„03+H.O = (Na.Ag)S+H„SO,. 

 This may then have come in contact with chlorine, decomposing part of 

 the solution which would again be reduced to silver chloride, and carried 

 along in suspension. In proof of this we have the deposits in Peru of 

 chloride of silver occurring in amorphous masses of sulphide of silver ; 

 the chloride of silver also occurs in Peru in the ferruginous rocks called 

 pacos, called in Mexico colorados, and in Cornwall by the Cornish 

 miners, gossan ; the chloride of silver of Huelgoet in Brittany, is 

 similar to this, occurring in cavernous hydrated oxide of iron. This 

 pacos is said to have resulted from the oxidation of iron pyrites. 

 Now, it is quite apparent that this chloride was not carried there 

 by the solution containing the constituents for the formation of 

 the iron pyrites, that is in solution, but it is possible that it was 

 carried there in suspension, or that a hot alkaline chloride solution 

 may have had it in solution and coming in contact with the solution, 

 destined for the formation of the pyrites which we may say was 

 cold, or at least at a lower temperature than it ; the silver chloride 



