Mr, Harcuerr’s Odfervations on Bituminous Subfiances, 14% 
ftances under which they are found, are alfo fimilar*. The whole, 
therefore, of the opinion in favour of fire, appears to reft on the 
volcanic nature of Iceland; but it furely would be going too far 
were we to afcribe to fire all the phenomena which are obferved 
in volcanic countries. ; 
Bovey coal, like the furturbrand, refembles half-charred wood; 
and I will allow, and indeed am difpofed to believe, that it isin a 
- ftate nearly fimilar;, but from this it does not follow that fire has 
- been the caufe, . é 
Carbon is known to be one of the grand principles of vegetables, 
and alfo as that which is the moft fixed, excepting the {mall por- 
tion of the earthscontained in them. sva fixed principle, carbon 
appears to form, in great meafure, the vegetable fibre; and after a 
certain degree of combuftion, (by which the other principles have 
been diffipated,) it remains, and the particles of it keep the fame 
arrangement which they poffefled when the vegetable was com- 
plete. pbinhowguer, the combuftion bail bean as on with the 
i bs rhs " : Pi, i ey 7 . 
brevi with funt adunata, ae autem. immanis Tequiritur vis, | ut truncus » .cylindricus 
ita complanetur ? Nonne antea_particularum nexus putredinis “quodam gradu fuarit 
relaxatus? Certe, nifi compages quodammodo mutatur, quodlibet pondus incumbens 
huic effetui ory bea /Czterim idem obfervatur ETE TY in omni fchifto argif- 
Jaceo. ; eabidoDs .bsist ; el 
Orthoceratitz, que in ftrato calcareo conicam figuram, perfect: Seala'y in fchifto 
planum fere triangulare compreflione eficiunt. Idem valet de pifcibus, conchiay. 4 in- 
fectifque petrefaétis. Caufa adhuc latet, fed in utroque cafu fine dubio eadem eft, et 
digna que exploretur.’ Obfervatu quoque dignum eft, quod idem reperiatur effe€tus, 
-quamvis ftratum calcareum fub fchifto collocatum fit et majori ideo pondere comprimente 
onufium. Bergman de Produdtis Vulcaniis Opufcula, tom. iii. p. 239+ 
* “It is found (the furturbrand) i in many pais 6 of Iceland, generally i in the mountains, 
in horizontal beds ; ; fometimes moré than one is to be met with, as in the mountain of 
Lack in Bardeftrand, where four ftrata of furturbrand are found alternately with different 
kinds of rasaal "= Troil’s Letters, p42) ki ' 
raihidino 2 3 free 
