^4 Baron Humboldt on Rock Formations. 
are referred. The English geognosts look upon the continent 
for their lias and red marl ; the German for their himte sand^ 
stein and muschelkalk. These words present themselves in the 
minds of travellers associated with remembrances of localities. It 
is not of so much importance, therefore, to produce precise ideas, 
as to make choice of localities generally known, and which are 
celebrated, either by the working of mines, or by descriptive 
works. 
In order to diminish the effects of national vanity, and to at- 
tach new names to more important objects, I proposed a long 
time ago, (1795), the denominations of Alpine Limestone,, and 
Jiira Limestone. A portion of the High Alps of Switzerland, 
and the greater part of Jura, are without doubt formed of these 
two rocks : the names, however, generally received at the present 
day, of Alpine Limestone (Zechstein), and Jura Limestone, 
should in my opinion be modified or entirely abandoned. The 
lower beds of the J ura mountains, filled with gryphites, belong 
to an older formation, perhaps to the zechstein ; and a great 
part of the limestone of the Alps of Switzerland assuredly is 
not zechstein ; but, according to Messrs de Buch and Escher, 
transition limestone. It would therefore be better to choose the 
geographical names of rocks from among the names of isolated 
mountains, the whole visible mass of which belongs only to a 
single formation, than to derive them, as I have erroneously 
done, from entire chains. I have thought, and many geognosts 
have formed the same opinion, that the J ura limestone (cavern- 
ous limestone of Franconia) was generally placed upon the con- 
tinent, beneath the Nebra sandstone, (bunte sandstein), between 
this sandstone and the zechstein. Subsequent observations 
have proved, that the name of Jura Limestone had with reason 
been applied to rocks which are very distant from the moun- 
tains of Western Switzerland; but that the true geognostical 
place of this formation, (when there is not a suppression of the 
inferior formations), occurs above the Nebra sandstone, between 
the shell-limestone (muschelkalk, or the quadersandstein), and 
the chalk. A geographical name, justly applied to several ana-^ 
logons rocks, renders us attentive to their identity of relative 
position ; but the place which homonymous rocks ought to oc- 
cupy in the total series, is not well determined except when the 
