30 Observations on the Change of 



which had a wa\T texture, and rather a glo?sy fracture; the 

 quality of this soit Ijcing apparently intermediate between 

 the others, as it retains completely the marks of its vege- 

 table origin, while, at the same time, it possesses every 

 perfect character of this species of coal. 



A. 200 grains of the Bovey coal, by distillation, yielded, 



Grains. 



1. Water, which soon came over acid, and after- 

 wards turbid, by the mixture of some bitumen 60 



2. Thick brown oily bitumen - - - - 21 



3. Charcoal -'- - - - - -90 



4. Mixed gas, consisting of hydrogen, ~\ 



carbonated hydrogen, and carbonic V estimated at 2y 

 acid, J 



200. 

 The charcoal, in appearance, perfectly resembled that 

 which is made from recent vegetables. By incineration, 

 about 4 grains of yellowish ashes were left, which consisted 

 of alumina, iron, and silica, derived most probably from 

 some small portion of the clay strata w hich accompany the 

 Bovey coal. But it is very remarkable, that neither the 

 ashes obtained from the charcoal of the Bovey coal, nor 

 those obtained from the leaves of the Iceland schistus, 

 atTordcd the smallest trace of alkali*. 



B. 200 grains of the Bovc)' coal, reduced to powder, 

 \\cre digested in boilinsr distilled water, which was after- 

 wards filtrated and examined ; but I could not discover any 

 signs of extract, or of any other substance. 



C. 200 grains were next digested with six ounces of 

 alcohol, in a very low degree of heat, during five days. A 

 vcllowish-brown tincture was thus formed, which, by eva- 

 poration, aflbrded a deep brown substance, possessing all 

 the pioperties of resin, being insoluble in water, but soluble 

 in alcohol and in ether; it also speedily melted when placed 

 on a red hot iron, burned with miich tiame, and emitted a 

 fragrant odour, totally unlike, the very unpleasant smell 

 produced bv burning '.he coal itself, or by burning any of 

 the common bituminous substances. The quantity, how- 

 ever, whicli could be extracted from 200 grains of the coal, 



* Tli'!^> .IS W.r ^s rchtes to the Bovey coal, lias btcii also noticed l>y 

 Di. Milles. Phi!. Trans- vol. li. p. i;?;. But wood, however loni; 

 !-ui>iiitrt;i-(i. is not ilipiivcd of nlkali, unless it has mere or less been con- 

 rcncd inio toal ; (oi I have, since the reading of this Pajicr, made some 

 (X[*criiiu: t« on the wnod of the su'Dmerged forest at Suuon, on the coast 

 'if Linc'iitishiie, and have found it to contain potash. 



