Mk. CtJRRiE on the Composition of some Fermented Liquors. 109 



it now only remains to be determined wlietlier the barriers at the mouths 

 of the glens consisted of ice, or of earthy materials. Perhaps we know 

 nearly as much regarding the latter as we ever can know ; but the valley 

 of the Spean has never been carefully examined, with reference to the 

 former passage of glaciers through it, by one fully competent to the task. 

 Till this has been done, geologists are not, I think, in a position to decide 

 between the rival theories. 



A new white Gunpowder was exhibited, invented by the assayer of the 

 mint at Constantinople, composed of sugar, chlorate of potash, and yellow 

 prussiate of potash. 



Ma/rch 20, 1850. — The President in the Quxir. 



The following papers by Professor Thomas Graham of London, were 

 presented by the author, viz. : — " On the Motion of Gases," Parts I. and 

 11. " On the Diffusion of Liquids.'' — Thanks voted. 



Mr. Bryce moved that the sum of £6 6s. be granted to purchase one 

 or two Aneroid Barometers for the use of an association of naturalists, 

 chiefly members of this Society, who were about to investigate the geology 

 and natural history of the basin of the Clyde. — The vote was agreed to. 



Mr. Stenhouse read a paper " On the Artifical Production of Organic 



A^ml 3, 1850. — Mr. Gourlie in the Chair. 



The following were admitted members, viz. : — Messrs. Thomas R. 

 Gardner, John Barclay, Robert Thomson, Thomas Neilson, Thomas 

 Davidson. 



Mr. Bryce's motion for a grant of £6 6s. for the purchase of an Aneroid 

 Barometer, was submitted to the Society for the second time, and finally 

 agreed to. 



Dr. R. D. Thomson communicated the following paper : — 



XIV. — Comioosition of some Fermented Liquors. By Mr. JonN Wright 



CURRIE. 



The mode of conducting the experiments was to weigh out generally 

 2000 grains of the liquor under examination ; it was distilled until the fluid 

 passing over gave no smell of aldehyde, or any green colour with bichromate 

 of potash and sulphuric acid. The distilled fluid, which consisted of alcohol 

 and water, and the residue formed of saccharine and albuminous matter, 

 were then weighed ; the diiferencc between the weight of the fluids 

 and that of the original fluid was the loss. The specific gravity of the 

 distilled fluid was then taken ; then by referring to a table the per centago 



