Report of the Progress of the Sciences in France. 431 
lherzolite, a blackish substance which seems to have some con~ 
nection with Gadolinite. Charpentier gave it the name of Pi- 
cotite, from the name of Picot de la Peyrouse. 
Mines of Tin discovered in France —Tin mines have been 
discovered near Limoges, and others at Pirac near Nantes. 
Of Rocks.—~The year 1813 has supplied us with various 
works upon rocks; but they have not all met with the approba- 
tioa of mineralogists, and they continue to adopt the nomen- 
clature of rocks given by the Germans, imperfect as it is. 
Pinkerton has published a work of considerable extent upon 
rocks. 
Other mineralogists have also proposed a new nomenclature 
for rocks : but it may be fairly thought that they wished them 
to have been unanimously rejected, for they are removed from all 
the philosophical principles of language. They gave, for exam- 
ple, the name of mimosa to a rock composed of feldspar and au- 
gite. Now there is no naturalist, or even amateur, who does not 
know that a celebrated plant, viz. the sensitive plant, is called 
mimosa ; when we read the word mimosa, who can tell whether 
a stone or a plant is alluded to? 
It would be useless to detail the other defects of works so 
unanimously disapproved. 
Crystailography.—After noticing Dr. Wollaston’s labours on 
the molecules of crystals, M. Delametherie proceeds :—Werner 
told me during his last visit to Paris, that he thought the figure 
of the primitive molecules of matter was spherical. 
Preschtal adopted the same opinion. Bodies, he says, do not 
crystallize but when they are in a liquid state. Now every fact 
seems to prove that the molecules of liquids are spherical. 
Descartes had published the same opinion. He said that the 
molecules of his two first elements, fire and the luminous fluid, 
were spherical. 
GEOLOGY. 
’ This branch of science has been this year the subject of the la+ 
bours of a great number of scientific men. Geology is equally 
advanced with the other branches of natural philosophy. It has 
problems, it is true, which have not been as yet resolved, but 
there are problems ia all the other natural sciences. 
Of primitive Earihs.—The primitive earths form the major 
part of our globe. The geologist cannot therefore study too 
minutely those with which we are acquainted, such as granites, 
porphyries, gneiss, schists, amygdaloids, the metals, the anthra- 
cites, &c. 
Charpentier jun. has given some interesting details respecting 
the Pyrenees. Hoff and Jacobi have visited, as intelligent mi- 
Bi Da neralogists, 
