300 Travels of a Naturalist in the Alps. 
same formation was examined at points where its thickness was less, 
petrifactions made their appearance. ‘The same holds true in the in- 
terposed marl, and in the members of the lias, the oolites and mus- 
chelkalk. When however, petrifactions do occur (which is some- 
what rare,) in the thicker portions of a formation, the same species 
are always smaller than when found where it is thinner, which fact 
has been observed also both by Sruper and Bove. Hver remarks 
still farther, that the petrifactions of the Jura prevail through the Al- 
pine chain generally, but less frequently and of a smaller size; and 
he suggests the law, that the larger the dimensions of mountain 
chains, the smaller are the size and number of their fossil contents. 
It is natural that such favorable opportunities for geological obser- 
vations as the Alps present, should suggest some theoretical views 
concerning the origin of formations; and whoever peruses this vol- 
ume would indeed be surprised if the highly imaginative tempera- 
ment of its author could be restrained to the humble, though often 
arduous, labor of mere description. Accordingly, commencing his 
concluding section but one, with the motto, ‘“ Sterilis est voluptas 
contemplandi nature opes, ubi ad illarum causas indagandas non 
procedit ratiocinatio,” he proceeds to give his theory, which may 
be stated succinctly as follows: There are three classes of formations, 
the primitive, secondary, and tertiary. The primitive is formed by 
crystallization or deposition from a fluid state. It includes two se- 
ries. The first embracing gneiss and mica slate was formed from 
without, inwards; the second consisting of muschelkalk (Alpine 
limestone,) lias and Jura limestone, was formed from within, out- 
wards. The secondary, to which belong granite, sienite, porphyry 
half granite, and also gypsum and dolomite, was formed from an in- 
ternal metamorphosis, (chemical change,) attended with the extrica- 
tion of gases and upheavings, before the primitive had reached its 
fixed state. ‘Tertiary, includes dolerite, basalt and lava, and was 
formed from the primitive or secondary by an internal metamorpho- 
sis after they had reached their fixed state. This metamorphosis he 
imagines to be the result of a living, active principle, pervading all 
nature. 
It is obvious that this theory is adapted with considerable skill to 
the phenomena of Alpine geology ; nor does it so far differ from the 
current notions in the science, as to be incapable of an easy transla- 
tion into such views. But to propose the living activity of the earth 
in explanation of geological appearances, is quite as remarkable as 
