Maclure’s Letters. 157 
in the history of the sciences. The society has just received 
from the Section des Indes, a package of beautiful plants, 
some of which were before unknown. On the same day 
and hour, the three foreign sections de I’ Inde situated at the 
Island of Maurice, of French Guiana and of Senegal will 
have made the same meteorological observations, which they 
will not fail to insert in the proces-verbal, destined for the 
parent society, in order that philosophers may compare them 
with each other. In those very distant.regions, this interest- 
ing feast will have been celebrated, which, renewed eve 
ear, and in such different places, cannot fail to spread, and 
inculcate more and more a taste for that noble science which 
is so intimately connected with our wants, and which deserves 
o be much more extensively cultivated and encouraged than 
it has generally been. 
Arr. XXV1.—Extracts from letters, addressed to the Editor, 
by Witu1am Macture, Esq. President of the American 
Geological Society. 
MOSAIC GEOLOGY. 
Dusuiy, June 30th, 1824. 
Dear Sir, 
“Faticuep and tired with the injustice, cruelty, 
oppression, and folly of despotism, I left Alicant on the day 
your two letters of January 23, and March 3, arrived. 
Your division* of the Mosaical Geology applies better to 
the transition and older secondary than any thing I have yet 
seen, and is, perhaps, as good a solution of what is completely 
out of our reach, as any other. 
The fact that the transition is at a constant dip, may be 
owing to its being disposed on the primitive, concerning 
which we can as yet scarce conjecture any thing, and may 
* That is, by epochs, corresponding with the order of time, described in the 
Genesis, and with the succession of geological formations, which we actually 
find, in the structure of the globe. This was briefly sketched in the letter 
alluded to by Mr, Maclure., 
