110 Analysis, -c. of Cordier’s Essay upon the 
“This opinion of a central fire slept, till it became obscurely 
revived by Des Cartes, Halley, Mairan, Buffon, and others; to 
whom it was suggested by some or all of the following conside- 
rations: 
“The figure of the earth; a globe flattened at the poles; 
pointing to an originally fluid state as necessary to produce it by 
revolutionary motion. 
: rtain astronomical phenomena. 
“'The mobility of the central mass, producing magnetic action. 
“The difference of temperature at the surface and at small 
depths. 
‘** Experiments on the cooling of incandescent bodies. 
“These considerations, however, failed to produce general 
conviction; and the aqueous fluidity of the globe, a theory ad- 
vanced by Pallas, aussure, Werner and his disciples, obtain- 
edt icy i es 
— oO 
288 
ee 
ities. 
This (Neptunian) theory of Werner, has been losing ground 
from the close of the last century to the present time. It may 
now be considered as universally abandoned.” 
It has been found, especially, that the substances ranked 
by Werner under the denomination of floetz-trap, have so 
strong an analogy in their appearance, their composition, 
mechanical and chemical, their position covering indiscrimi- 
nd h we, in other cases, so man analogies with known 
volcanic ejecti 
“Tn aid of thislast and modern theory, (the Plutonian,) come 
the experiments on the ‘radiation of caloric into atm i 
pace ; the tion of caloric fi lecule to molecule ; 
and certain mathematical considerations of a general nature; as 
well as the small distance to which solar heat penetrates into the 
surlace of the earth; and the depth where a fixed temperature 
has been bserved. Late experiments also have shewn, 
