18 



tested and oxaminod with a view to determine their che- 

 iiiiral constitution and commercial value, and he now re- 

 marked, if he were to attempt, by an uninterrupted series of 

 experimental investis:ations to bring before the Institution all 

 that might be said or done as respects the chemistry of 

 metallic bodies, their Ores, Oxides, &c. , he should be 

 trespassing at an inordinate length upon their time and 

 patience ; he therefore proposed, as the subject generally 

 had already been explained to the Institution, occasionally 

 to devote an evening to this species of research, when it 

 would be his object, as in the present instance, to enter upon 

 the Analysis, Chemical constitution, properties and uses of 

 individual specvhcns of the Ores, the Metals, their Oxides, 

 Chlorides, &c. 



Mr. W. now commenced his experimental demonstrations 

 by analysing 100 grains of the Malachite or Green Carbonate 

 of Copper, which he shewed to consist principally of the 

 Metal in combination with Carbon. The following are the 

 Analytical proportions deduced from the operation, the sub- 

 ject of which was a specimen selected from the mineral 

 cases of the Museum. 



Copper _ - - - 56,5 



Oxygen _ - - 17,3 



Carbonic Acid - - 11,2 



Water - - - - - 15, 



100,0 



A portion, weighing 31 grains, detached from the same 

 specimen, was also reduced to the Metallic state by assaying 

 upon Charcoal under the operation of the Lecturer's Gas 

 Deflagrator. The Metallic copper yielded in this experiment 

 amounted to 13,5 grains, and the reduction was completed 

 within twelve seconds. 



Similar analytical illustrations were introduced with the 

 peroxide of Manganese, terminating in its reduction to the 

 state of a pure Metal, with Galena, various ores of iron, 

 together with many experiments to elucidate the formation 

 and uses of their respective Oxides, Chlorides, and other 

 combinations. Mr. W. apologised for a digression he made 

 at the close of the lecture, by directing the attention of the 

 audience to a phenomenon which had occurred incidentally 

 during one of his preceding experiments, from the falling of 

 globules of melted iron at an extreme degree of heat into a 

 vessel of water, whereby they acquired a very extraordinary 

 motion, and were suspended for 2 or 3 seconds, a few lines 

 above the real surface of the liquid, while they presented 

 a most intensely dazzling brilliancy. The principal 



