NATIONAL INSTITUTE. 



One of our late French papers contains the Report o£ 

 the National Institute at Paris, for tlie year 1810. The 

 following is an abstract of the rnqst irUeresting part. 



Messrs. Guy, l^ussac, and Thenard, have directed thei;- 

 JVttcntion to compare the relative powers and energies oi' 

 different .<jalvanic piles, i'iiey have discovered, that the 

 force of the pile is not increased in proportion to the 

 Dumber of plates. To produce a double ctfect, the num- 

 ber of ])jates niust be increased eiglit times. In genera^, 

 i^ was foiinfi that (ht; 0')a,ntity of gas the piles will pro- 

 duce, is nearly in proportion to the cube root of the num- 

 ber of plates employed. Amongst the discoveries tu 

 which the galvanic pile has given rise, there are few 

 piore interesting to general chemistry than the transfor- 

 mation of the alkalies into combustible substances of 

 metallic spler.doro' 



The transformation, first discovered by Mr. Davy, W!\% 

 ai'tervvarda doubted by Messrs. Lussac and Thenard 

 In then- former report they were disposed to consider 

 potassium and sodium as combinations of the alkalies 

 wiih hydrogen, and p class them amongst the compound 

 substances called hydrurets ; subsequent experiments 

 Jfcave led them to inchne to the opinion of Mr. Davy, and 

 to regard potassium and sodium as simple metallic sub- 

 stances. 



]M. Berthollethas communicated a process formakinof 

 |hc muriate of mercury, called mercurius dulcis or calo- 

 mel, by passing oxygenated muriatic gas through mercu- 

 ry ; it combines i-apidly with the metal, and forms witb 

 it the muriate of mercury ; and us this metallic salt has a 

 perfect analogy with oiher mercurial salts, produced by 

 other acids and mercury, at the miiumum of oxydation, 

 lie concludes that the mercury in forming this combina- 

 tion has been reduced to an oxyd by the oxygcoe of the 

 acid, and nor by that of the water. 



