ns
stalactiques dont elles s'ornent. Quelques-unes de ces grottes ne
peuvent etre attribuees qu'a quelque bouleversement des couches;
d'autres semblent devoir leur origine a l'ecoulement des sources
souterraines qui ont amolli, ronge et charrie une partie de la roche qui
en etoit susceptible.

"En s'eloignant de la chaine, on voit les couches calcaires s'aplanir
assez rapidement, prendre une position horizontale, et devenir
abondantes en toute forte de coquillages, de madrepores, et d'autres
depouilles marines. Telles on les voit par-tout dans les vallees les
plus basses qui se trouvent aux pieds des montagnes (comme aux environs
de la riviere d'Oufa); telles aussi, elles occupent tout l'etendue de la
grande Russie, tant en collines qu'en plat pays; solides tantot et comme
semees de productions marines; tantot toutes composees de coquilles et
madrepores brisees, et de ce gravier calcaire qui se trouve toujours sur
les parages ou la mer abonde en pareilles productions; tantot, enfin,
dissoutes en craie et en marines, et souvent entremelees de couches de
gravier et de cailloux roules."

How valuable for science to have naturalists who can distinguish
properly what they see, and describe intelligibly that which they
distinguish. In this description of the strata, from the chain of
mountains here considered as primitive, to the plains of Russia, which
are supposed to be of a tertiary formation, our naturalist presents us
with another species of strata, which he has distinguished, on the one
hand, in relation to the mountains at present in question, and on the
other, with regard to the strata in the plains, concerning which there
is at present no question at all. Now, let us see how these three things
are so connected in their nature, as to form properly the contiguous
links of the same chain.

The primary and tertiary masses are bodies perfectly disconnected;
and, without a medium by which they might be approached, they would be
considered as things differing in all respects, consequently as having
their origins of as opposite a nature as are their appearances. But the
nature and formation of those bodies are not left in this obscurity;
for, the secondary masses, which are interposed, participate so
precisely of what is truly opposite and characteristic in the primary
and tertiary masses, that it requires nothing more than to see this
distinction of things in its true light, to be persuaded, that in those
three differen