French Nallonal Institute* 235 



animates the learned of various conntrifs. Scarcely had we 

 been apprised in France of the discovery of Daw, on the 

 chances which potash and soda undergo bv the aciion of 

 the Voltaic |)i!e, when two of our young chemists,- M. Gay 

 Lnssac, member of the class, and Al. Tlienard, professor 

 in the college of France, endeavoured to produce ihe^ same 

 effect by the common affinities, and succeeded by means of 

 apparatus most Ingeniouslv contrived*. 



The public journals having announced that laminated 

 zinc had been applied to several useful purposes in England, 

 it is but justice in us to reclaim this appliLaii:)n of lami- 

 nated zinc as a French imj/rovemem. M Macouer and 

 M.. Sage long ago performed this process bv Leating the 

 metal : but we have to notice another recent improvement 

 on this subject in France, namely, the art of converting, 

 by simple sublimation, calamine or oxide of zinc into me- 

 tal suthciently pure to undergo lamination. Messrs. Oonq 

 and Poncellet have, in the department of the Onrlhe, lately 

 succeeded in this operation, and the ore furnished them 

 with one-third of its weight in metal. This laminated zinc 

 may be employed on almost all occasions, instead of sheet 

 lead, and it will be found much cheaper. 



Another application of chemistry, not less inlerestino- to 

 society, is the art of preparing with wood an acetic acid 

 equally pure with radical vinegar. This was suggested by 

 Messrs. Fourcroy and Vauquelin, who discovered that the 

 acid which goes by the name of pyro-lig>teo?i,s, and is pro- 

 duced by the distillation of wood, is only the acetic acid 

 mixed witli some foreign substances. On freeing it from 

 these, M. Mollerat has procured an acid which may be 

 used as a substitute for common vinegar; but it is more 

 acrid than the latter. 



The interrupti(m of our colonial intercourse has repeat- 

 edly suegested the employment of some substitute for suo-ar, 

 and M. i'armenticr has recently published some popular 

 instructions on the art of extracting from the must or juice 

 of the grape, a syrup, in order to supply the place of suoar; 

 he has presented some excellent specimens of this syrup to 

 the Institute, and great quantities of it are now manufac- 

 tured in our southern provinces : the interruption to the 

 exportation of our wines is an additional encouragement to 

 this manufacture. The grapes of the south of France, bein"- 

 Ijaiuially sweeter, give proportionally more sugar; and cart* 



• Se« Pliilosopliical Magazine, vol. xxxii. 



TIKlSt 



