LAWSON ON THE IMPROVEMENTS IN AMALGAMATION. 11 



quantities. Much of the pitch manufactured on the island is taken 

 from the lake. AVhen thrown into heaps it runs together inta a 

 solid mass. And the place from which it is taken, although near 

 the side of the lake where the pitch is hardest, gradually fills up 

 again by the pressing in of the surrounding mass. The supply 

 being so large and so easily attainable, it must continue for ages of 

 vast economic importance. 



Art. IX. Ox some Recent Improvements in the Amalgama- 

 tion Process for Extracting Gold from Quartz. By 

 George Lawson, Ph. D., L. L. D., Professor of ChemistKij,. 



-Dalhousie College. 



IRead March 8, 1866.] 



The paper was chiefly occupied with a discussion of the proper- 

 ties of the metal Sodium, (Na.) and of the Sodium Amalgams, and 

 of the use of the latter in promoting the amalgamation of Gold. 



The metal sodium, a discovery of Sh Humphrey Davy, was 

 particularly described, and the method of removing it from its com- 

 bination with oxygen. It was prepared by decomposing carbonate 

 of soda by means of charcoal, at a high temperature, this last having 

 a greater affinity for oxygen than sodium. The use of sodium in 

 the arts has so diminished its price that it can now be obtained at 

 6s. stg. per lb. . Specimens of large size, contained in naphtha, were 

 exhibited. Its colour is silver white, sp. gr. 0.972 — it is as soft as 

 butter at the ordinary temperature of the atmosphere, fuses at 194°, 

 and oxidizes rapidly in air. It^burns on a slight increase of tempera- 

 ture. Several interesting experiments of its fusion and burning 

 were exhibited. It decomposes water rapidly, uniting with the 

 oxygen it contains, and liberating the hydrogen. The Doctor 

 illustrated its action on water by some beautiful experiments, — 

 amongst others, by the preparation in course of a few minutes of a 

 large jar of hydrogen gas, by the action of sodium upon water ; the 

 hydrogen was afterwards exploded to show the converse of the 

 experiment. The property of sodium in promoting the action of 

 mercury and amalgams upon other metals had been known for many 

 years. Recently, however, Mr. Crooke, F.R.S., a distinguished 

 chemist, who had discovered the metal thallium, has applied, sodium 



