Scientific Newt, Accitmts ofBooks^ iff^, a'jg 



je£l will form tlic bafis of more ample comrtiuiiication and rcfearch, I fliall not here attetjipt 

 to give any more concife abridgement of the communications to the Inftitutet '.rot-joi; . 



Mineralogy -r-Coiicerning arfeniated Coppet- in Plates.. This mineral from CornwaH, jyien- 

 tioned by forae; German chemifts, but little known in France, haa beeti (Jefcribed by 

 Lelievr!e,t.and;aaalyfe4 rby Vauquelin. It cryftallizes in brilliant hexagonal platesj jtr^ft ' 

 parent, olive-green, w^hich decrepitate in the flame of a candlej to which they give a green 

 colour ; it is very difucultiy fufible by the blow-pipe, emits a fmell of garlic, colours boraX 

 green with reddilh zones, and is foluble with efflorefcence in the nitric acid, to which it 

 gives a flight green colour. 



Geology. — On the Eruption of Mount Vefuvius in the fecond Republican Tear .-^-Onz of the 

 moft important points to be determined in the hi (lory of voleanos, is the degree of heat 

 neceflary to give fluidity to the lavaS. Is this fire flmiiar.in intenfuy. to that which prpV 

 duces glafs ? or is the fluidity owing .to fome other caufe ? Dolomieu has been long em- 

 ployed on this queilion. The eruption of Vefuvius in the fecond year afforded him th» 

 means of afcertaining this degree of heat almoft thermometricaliy. He found that this 

 heat is not greaterthan fufes filver, hut lefs than is required to lufe copper. Th6-met>U 

 capable of being oxided at a lefs heat than that which is required tofiifp them, ■ha.ve. been 

 oxided in the centre. of the mod voluminous mafies. Lead riwasi, -converted into tefliifej 

 galena witli large fcales, glafs into Reaumur's porcelain, &c.: • .- ■ 



On the Belemnites.—4Z\vkZtn^a.gt, who dcfcribed feveral.new fpecies of this foflil in ihe 

 Jffliurnalde PhyCque, communicates in this article fome othors, ^hich at that time he had 

 not feen. • f 'mi ■ ' ;', ' ■ ' ::-;;;. j i. ' . .J 



Meteorology. — Agreement hettJMen the.Variations:cf 'the- Atmofphere ovemk great Extent sf 

 Country — ^The labours of Citizen Larharkj to^termine whether the variations of the.at- 

 mofphere be governed by any periodical lavt^ are well known. On the prefent occafion be 

 has endeavoured to afceitaih whether thefe variations extend to great dhlances. Eor with- 

 out this condition, every method. of predicting the atmofpheric changes mufl undoubtedly 

 be merely local ; and- difi^crent rules Would be required, .even ■ for the greater -variations, at 

 each different place. His prefent inquiries are confined to the barometrical changes. He 

 traced twcnty-fix parallel lines upon paper, to reprefent the ftations or heights at which the 

 barometrical column flands in our climate. Other perpendicular lines reprefent the days 

 in fucceflion. By this ingenious contrivance (which was adopted very early in the ladl 

 century) he was able to exhibit a curve denoting the bavo.merrical variations for any given 

 courfe of time. But the inquiries of Lamark demanded,. 4Jvat he- (houid trace in Jjhe. fame 

 pidlure the lines for different places. One of thefe anfwers to the obfervatory at Paris; a 

 feco;id to the refidence of Citizen Pi£lot of Geneva ; a third to that of C- Thulis at Mar- 

 feillcs; and he found that thefe lines afcend and dtfcend generally together, a i;d differ 

 fcarcely at all, but according lo the height of the place of obfcrvation, , or the extent of the 

 variations, but not their direction. 



Zoology^— 



