472 
OPINIONS OF CELEBRATED PHILOSOPHERS. 
Bernax'd Palissy, a potter of Saintes 
towards the end of the sixteenth century, is 
said by Fontenelle to have been the first who 
ventured to assert in Paris, in opposition to 
the prevaling opinion, that petrified shells 
were the remains of testaceous animals that 
had formerly lived in the sea, and that all 
these were not deposited at the universal 
deluge. He wrote on the Origin of Springs 
from Rain-water, and other scientific works ; 
and he had the merit of displaying much 
juster views of the operations of nature than 
most of his contemporaries , though his ideas 
met, in his own time, with a very faint re- 
ception. Similar notions were advocated by 
Isi icholas Steno, a Dane, who became professor 
of anatomy at Padua in Italy, in 1669 ; and 
Hooke and Hay, in England, distinguished 
themselves by opposing facts to visionary 
theories. 
Leibnitz, in his Pi-otogsea, published in 
1680, advanced the bold hypothesis, that the 
earth was originally a burning luminous 
mass, the gradual refrigeration of which 
produced the primitive rocks, forming at fiist 
a solid crust, and this being ruiitured, owing 
to irregular contraction, the fragments fell 
into the universal ocean formed by the con- 
densation of vapours on the surface of the 
globe. He proceeds to trace the production 
of inundations, convulsions, and attrition of 
solid matter, by its subsequent deposition 
constituting the various kinds of sedimentary 
or stratified i-ocks. Hence, he observes, may be 
conceived a double oidgin of primitive masses ; 
( 1 .) By cooling after igneous fusion; (2.) 
By re-concretion from aqueous solution.* 
“ Here,” says Mr. Conybeare, ” we have 
distinctly stated the great basis of every 
scientific classification of rock formations. ”+ 
The grand feature of the theory propounded 
by Leibnitz, relative to the candescent state 
and gradual cooling of the earth, was adopt- 
ed only by Whiston, but likewise more I’e * 
cently by BuflFon, Deluc, and other theorists. 
Among those men of science who con- 
tributed to the improvement of geology, by 
their researches into the actual structure of 
the earth’s crust, was Tilias, a Swede ; who, 
aware of the importance of an exact know- 
ledge of mineral bodies, published in 1750 
several topographical descriptions illustrative 
of the geology of certain districts in Sweden. 
He was followed by Lehman, a German mi- 
neralogist. dii’ector of mines in Prussia, who, 
in an Essay towards a Natural History of 
the Sti’ata of the Earth, 1756, proposed a 
division of mountains into those formed 
before the creation of animals, and contain- 
ing no fragxnents of other rocks ; mountains 
which were derived from the partial destruc- 
tion of the primary rocks by a general i-evo- 
lution ; and those which resulted from local 
•“ Unde jam duiilex origo iutelligitur prl- 
nxoruin corporuin, una, cum ab ignis fusione 
refrigescereixt, aliera, cum reconcrescereat 
exsolutione aquarum.'* 
t Progress, Actual State, and Ulterior Pros- 
pects of Geological Science, iu Report of Bri- 
tish Association for x83i, p, 368 , 
revolut ons, and in part from the Noachian 
deluge. 
Many other writers now appeared, who 
advantageously directed their attention to 
the investigation of particular topics connect- 
ed with this subject; as the causes and phe- 
nomena of earthquakes and volcanos, the 
formation of deltas or low tracts at the 
mouths of rivers, the actual structure and po- 
sition of the minei'al strata, and the descrip- 
tion of fossil remains of animal or vegetable 
origin. Among those who I’endered import- 
ant services to the cause of science by ad- 
vancing general views of the theory of the 
earth, were Dr. James Hutton, of Edin- 
burgh and Professor Werner, of Freyberg, 
in ^Saxony. These celebrated philosophers 
produced systems, in one respect, diameti’i- 
cally opposite to each other ; for while Hutton 
attributed the formation of the older rocks 
entirely 10 the agency of fire, Werner insisted 
that they originated from solution in a liquid. 
The German geologist deserves the cre- 
dit of having directed the attention of his 
pupils to the constant relations of mineral 
groups, and their regular order of superposi- 
tion; distinguishing the classes of pi’imary 
rocks, or those destitute of organic remains, 
as granite and gneiss; transition or secon- 
dai’y rocks, formed from the disintegration of 
the preceding, and occasionally exhibiting 
traces of organic remains, as gx’eywacke, a 
mechanical compound of agglutinated frag- 
ments ; floetz or tertiary rocks, including the 
coal sti'ata, chalk, and freestone, some of 
which abound in organic relics ; and besides 
these, alluvial strata and volcanic rocks, the 
latter of which he seems to have regarded as 
of little importance, for he asserted that in 
the primeval ages of the world there were no 
volcanos. 
The great merit of Hutton consists in 
his having demonstrated the igneous origin 
of basalt, and other trap rocks ; the high 
probability that granite is derived from the 
same source ; and that the other primary 
non fossilliferous rocks have been more or 
less subjected to the agency of fire. ‘‘ The 
ruins of an older woxdd,” said Hutton, ” ai*e 
visible in the pi’esent structure of our planet, 
and the strata which now compose our con- 
tinents have been once beneath the sea, and 
were formed out of the waste of pre existing 
continents. The same forces are still de- 
stroying, by chemical decomposition or me- 
chanical violence, even the hardest I’ocks, 
and transporting the materials to the sea, 
where they ai*e spread out, and form strata 
analogous to those of more ancient date. 
Although loosely de[)osited along the bottom 
of the ocean, they become afterwards altered 
and consolidated by volcanic heat, and then 
heaved up, fractured, and contorted.”* 
The theory of Hutton was admirably 
illustrated and ably supported by Professor 
Playfair, of Edinburgh, while it was assailed 
* Lyell’s Principles of Geology, 3d ed., 18 4, 
vol. i. pp, 88, 89 ; from Hutton’s Theory of the 
Earth, 
