Foreign Literature and Science. 385 



to 9 inches long destined to receive the substance to be acted 

 upon by the solvent. It is closed at bottom by a cork a, a, (see 

 pi. lO, fig. 5,) through which passes the small tube 6, b, open 

 at each end, except that it is covered with muslin at x to 

 prevent the pulverised substance from passing into it. One 

 half of the tube A is filled with the vegetable powder, and 

 the other half with the fluid. The small tube is adapted by 

 means of a cork to the small globe B, freed from air by a 

 few drops of alcohol, which by the application of heat ex- 

 pands into vapour and expels the air. The small tube is 

 then tightly pressed into its neck, and the apparatus is set 

 in a cool place. As the alcoholic vapour contracts and then 

 forms a vacuum, the pressure of the air forces the liquor 

 through the pulverised mass and thence into the globe. In 

 a few minutes a portion of extract is thus obtained, which 

 being withdrawn, the vacuum may be renewed by alcohol, 

 and the process thus continued at pleasure. 



14. j1 Steam Boat either has been, or is about to be con- 

 structed on the Lake of Geneva in Switzerland by our coun- 

 tryman Edward Church ; who was the first to bring steam 

 navigation into successful operation in France by the estab- 

 lishment of a steam boat on the Garonne. The Swiss boat, 

 (the first, it is believed, yet attempted in that romantic coun- 

 try) will ply between Geneva and Lausanne, stopping a 

 few minutes at Copet, Niou, Rolle and Merges, and pt;r- 

 haps extending her voyage occasionally to Vevey and the 

 Chateau de Chillon. A more picturesque and delightful 

 navigation can scarcely be conceived. 



15. Vesuvius. — By a letter from Naples dated Novetn- 

 ber 5th, 1822, published in the Bii. Ui.iv. of Geneva foi' the 

 same month, it appears that the eruption of Vesuvius which 

 took place on the 22d of October was as terrific as any that 

 has occurred since A. D. 79 described by Pliny. Day was 

 turned into night by the clouds of ashes and other volcanic 

 matter, which at a distance from the mountain, fell to the 

 depth of 5 and 6 feet. The writer collected several pounds 

 of the ashes from his Balcony in Naples. It was al first of 

 a reddish brown, and then more white, and appeared to him 

 like pulverised pummice stone. He states that it had been 

 analysed by M. Pepe who found in it sulphate of potash, 



Vol. VI.— No. 2. 49 



