LAMARCK’S WORK IN GEOLOGY ToT 
mountains, which are generally arranged in more or 
less regular chains. But he strangely assumes that 
the constituents of granite, z.¢., felspar, quartz, and 
mica, did not exist before vegetables, and that these 
minerals and their aggregation into granite were the 
result of slow deposition in the ocean.* He goes so far 
as to assert that the porphyritic rocks were not thus 
formed in the sea, but that they are the result of depos- 
its carried down by streams, especially torrents flowing 
down from mountains. Gneiss, he thinks, resulted from 
the detritus of granitic rocks, by means of an inappre- 
ciable cement, and formed in a way analogous to that 
of the porphyries. 
Then he attacks the notion of Leibnitz of a liquid 
globe, in which all mineral substances were precipitated 
tumultuously, replacing this idea by his chemical no- 
tion of the origin of the crystalline and volcanic rocks. 
He is on firmer ground in explaining the origin of 
chalk and clay, for the rocks of the region about Paris, 
with which he was familiar, are sedimentary and largely 
of organic origin. 
In the “Addition” (pp. 173-188) following the fourth 
chapter Lamarck states that, allowing for the varia- 
tions in the intensity of the cause of elevation of the 
land as the result of the accumulations of organic 
* Cuvier, in a footnote to his Yzscours (sixth edition, p. 49), in 
referring to this view, states that it originated with Rodig (Za Physique, 
P. 106, Leipzig, t8or1) and De Maillet (Ze//iamed, tome ii, p. 169), 
‘*also an infinity of new German works.”” Headds: ‘‘ M. de Lamarck 
has recently expanded this system in France at great length in his 
Hydrogéologie and in his Philosophie zoologique.” Is the Rodig re- 
ferred to Ih. Chr. Rodig, author of Bettrdge sur Naturwissenschast 
(Leipzig, 1803. 8°)? We have been unable to discover this view in De 
Maillet ; Cuvier’s reference to p. 169 is certainly incorrect, as quite a 
different subject is there discussed. 
