344 
ture, is unworthy of the smallest atten- 
tion. Nor is much more due to those 
systems which suppose, at some particu- 
lar period of time, the existence of a 
fluid and chaotie mass, in which various 
particles of matter w ould, im the general 
jumble, be mutually attracted by chemi- 
€al affinities, and the heavier and grosser 
parts sinking towards the centre, form 
there a solid ball: for neither is it al- 
lowed, in philosophical investigation, to 
have recourse to arbitrary suppositions, 
nor are the different materials that enter 
into the composition of this terraqueous 
globe,as far as we have been able to pene- 
trate, either by means of natural or arti- 
Rear excavations, arranged according ‘to 
their specific gravity. 
Of the celebrated system of Buffon it 
may with truth be afhrmed, that it is an 
ingenious combination of ideas and facts, 
though in some respects it is almost as 
miraculous ‘and arbitrary as that of a 
fluid and chaotic mass. It supposes the 
earth to be a combined vitreous mass, 
consisting of a comet, and a proportion 
of the exterior part of the sun, which af- 
ter it was sufficiently cooled in the lapse 
ef time, perhaps hundreds of thousands 
of years, has gradually assumed its pre- 
sent form. From the phenomena of vol-. 
canoes, or frequent explosions of subter- 
raneous fire, witnessed every day in dif- 
ferent climates and regions of the earth, 
and from universal traces of the opera- 
tign of fire, he concludes that the whole 
earth was once in a state of fusion. It 
still contains a central heat, though this 
constantly evaporates, and is gradually 
dissipated. There is in nature a scale of 
the degrees of heat whose upper extre- 
mity is the point where all fluids heated 
by the action of fire, and in .a state of 
constant ebullition, would-be volatilized : 
where the most fixed earthy particles, di- 
vided aud attenuated by those of fre, 
would in like manner fly off m vapour; 
and by which, were it prolonged, the globe 
itself, though formed and consolidated by 
the power of g ravity, would be destroyed 
by the expansive force of this element, 
The other point, at the bottom of the 
scale, is that ares this force no longer 
animating nature, a living beings w ouid 
perish, and every fluid substance be con- 
gealed ; where ithe air itself, being de- 
prived of its spring, would fall down upon 
the torpid earth, therewith to form but 
one dead and solid mass. Ayreeably to 
this doctrine, Mr. de Buffen is convinced 
that several of the planets cannot now be 
inhabited: some by reason of an excess 
The Engutrer.—No. XXIP. 
[Sept. I a 
a heat ; others by reason. of an excess 
of cold. Jupiter, for example, still 
highly impregnated with fire, leoks for- 
ward, according to Buffon, to the epock 
of living beings, which he will not see for 
many thousand of years. The Frozen 
Moon has: not a single inhabitant. The 
globe that we inbabit, heated up in some 
former period to the point of ignition, is 
gradually cooled down, though very 
slowly, by reason of its prodigious mass. 
The aged earth loses its internal heat in 
the course of time, as we, when we be- 
come old, lose that which gives us anima~ 
tion 
Prior to Buffon, Mairan was ded: by 
certain observations. on -the , earth, to 
Maintain that it possessed, in itself, a 
heat not derived from the-sun. He 
termed it central, because, as it propa~ 
gated itsgenial influences-to every part of 
the earth's surface, it seemed to act as 
proceeding from a central point: though 
he did not pretend, by this specification, 
to determine, like Bufon, either the place 
or the cause which produced those effects. 
Leibnitz did not hesitate to affirm. that 
the earth owed its form, and the consis- 
tency of its matter, to the element of, 
fire. Des Cartes, in his day, imagined 
that the earth, and other planets, were 
nothing but so many little incrustated. 
suns. 
Thus I have given an cuttin of the 
geological systems which divide geolo- 
gists. These systems rest on the re- 
spective bases of water and of fire: and 
therefore, they who respectively maintain 
them are called Neptunists or Vulcanists: 
According to the Neptunists, the cen- 
tral part af this globe. consists of the 
stone known by the name of granite. 
This substance they consider as the nue 
cleus of the globe. And it is upon-this. 
substance they think that all matters on 
the surface, and near the surface, rest. It 
consists in general of an assemblage of 
siliceous stones, such as quartz, schorl,. 
and feldspar, which owe their arrange- 
iment to water. In the reign Of a fluid 
and chaotic mass, the water, as thesleast 
heavy principle, must have purified itself, 
and arisen, throavh the other materials, 
by filtration ; ; while the earthy principles 
must have bcen-precrpitated, and formed 
a mud, in which ali the elements of stone 
were confounded. That there is a cen- 
tral body in the globe, which supports 
those parts that come to be more unmedi- 
ately exposed to our view, is agreed-on 
both by the Neptunists. and Vulcanists. 
The greater part of the Vuleanists hke= 
Wise. - 
