31d Extracts from the third Volume of 



A hundred parts of elastic resin, analyzed in the dry \vay:> 

 were therefore decomposed into : 



Carbonated hydrogen - 



Carbonic acid - - 



Bituminous oil 



Acidulous phlegm 



Charcoal _ _ - 



Lime _ - _ - 



Silex - - - - 



Oxide of iron _ - - 



Sulphate of lime - 



Alumine 



of which, however, the. five last only are Immediate prin* 

 eiples of the fossil caoutchouc, while the other five exhibit, 

 products of the. natural combination of the carbon, hydro- 

 gen, and oxygen contained in this fossil, but altered by 

 the fire. , ■ 



iS^othing is found in the results of this analysis which can 

 throw any light on the explanation of the elastic property 

 possessed by this singular fossil : we must, therefore, ad- 

 here to the opinion of Mr. Hatchett, who ascribes it ta 

 small molecule of air, intexpo^ed in. the pores of the resin, 

 accumulated during its formation in a manner still un- 

 known,. 4nd which communicates to its whole mass an 

 el^astJG and spongy consistence. 



. Analysis of.Peat-E.arth (tourbe). 



Peat earth, formerly denoted by the' name of ligneous 

 earth, bitiiminous earth, isdug up in great abundance in 

 the county of Mansfield, and m the circle of Saal, where 

 it is found in considerable strata, almost always at a little 

 depth below the vegetable earth. It has a blackish colour,; 

 and an earthy fracUue. It communicates a little tint to 

 bodies on which it is rubbed. It is dull, easily pulverised, 

 and in the air falls- -a-imost into dust. It is a very useful 

 combustible, which is prepared by softening it in water, 

 moulding it like bricks iri wooden mouldSj'and then' leaving 

 it, to dr)'- in the air. ' ■ 



Its appearance and-tektare prove that it has originally- 

 formed the fibrous part of a large quantity of wood, depo- 

 sited by water, whirh has become altered in its immediate 

 principles, butwliich has not entirely lost its structure. 



The peat earth emploved in tlie following analysis was 

 dug up in the royal baJiwick of Schraplace. 



Exp. J, TwQ hunUi-ed grains of this fossil, put into a 



