456 THE CANADIAN NATURALIST. [DeC. 



reason why similar results should not be obtained there. I am 

 the more anxious to obtain the opinions of these gentlemen, because 

 I learn that for years to come further attempts are to be made 

 to carry ova in ice to that colony." 



NEW METHOD OF EXTRACTING GOLD FROM ORES. 



Mr. Briggs read a paper from Mr. F. C. Calvert, of Manches- 

 ter, on a New Method of Extracting Gold from Auriferous Ores. 

 At the present time when the auriferous ores of Great Britain are 

 attracting public attention, it may be advantageous to persons 

 interested in gold-mining, to be made acquainted with a new and 

 simple method of extracting gold from such ores, which presents 

 the advantages of not only dispensing with the costly use of mer- 

 cury, but of also extracting the silver and copper which the ore 

 may contain. Further, it may be stated that the process can beprr_ 

 fitably adopted in cases where the amount of gold is small, and the 

 expense of mercury consequently too great. Without entering here 

 into all the details of the numerous (about one hundred) experiments 

 which I made some years since, before I finally arrived at the new 

 method of extracting gold, which I have now the honor of com- 

 municating, allow me to state a few facts which are necessary to 

 give a complete view of the subject. If 2.2 parts of pure and finely 

 divided gold, o'.>tained by the reduction of a salt of that metal, be 

 added to 100 parts of pure sand, and placed in a bottle with a satu- 

 rated solution of chlorine gas for 24 hours, only 0.5 of gold is dis- 

 solved. If the same experiment be repeated, but instead of chlorine 

 water, a mixture of chlorine water and hydrochloric acid be used, 

 0.6 of gold is dissolved. If, instead of employing hydrochloric 

 acid and chlorine gas, a mixture of sand, reduced gold, and perox- 

 ide of manganese, with hydrochloric acid, are placed in a bottle, 

 i.4 of gold is dissolved ; so that it would appear that, under the 

 influence of nascent chlorine, the gold is more readily dissolved 

 than when the same gas is mixed in solution with hydrochloric acid, 

 previously to being placed in contact with the auriferous sand. Still 

 these processes leave a great deal to be desired in a commercial 

 point of view, as more than a third of the gold remains undissolved. 

 The same results are obtained if the chlorine gas be generated by 

 another method, viz., by adding to the auriferous sand a mixture 

 of chloride of sodium, sulphuric acid, and peroxide of manganese. 

 Being convinced, therefore, that nascent chlorine gas was a fit and 

 proper agent for cheaply extracting gold from ores,and that it was pro- 

 bably only necessary to modify the method of operating, I allowed 



