Retrofpel of French Literature,—Mifcellaneous. 
winter is very mild and the fpring 
rainy, the florifation of vernal plants 
is of courfe anticipated by thirty or 
forty days ; and that when the fpring 
is cold, this operation is retarded inthe 
fame proportion. Nature, indeed, re- 
fumes her right in the months of June, 
July, and Auguft; for the fummer-., 
plants, when attended by fimilar cir- 
cumftances, flourifh every year at the 
fame periods, It ought alfo to be ftated, 
that during thofe feafons when the 
north winds prevail in the warm 
months, the development of flowers, 
as well as the maturity of fruits, Is re- 
tarded for feveral weeks.” 
‘* Hiltoire de Conferves d’eau Douce, 
contenant leurs differens Modes de Re- 
production, & la Defcription de leurs 
principales Efpeces, &c.”—A Hiftory of 
the treth Water Conferve, containing an 
Account of their different Modes of Re- 
production ; and alfo the Defcription of 
their principal Species, &c. by JouN 
Vaucker, Minifer of the Gofpel at 
Geneva, Profeffor of Botany, Member 
of the Society of Natural Hiftory, and 
of the Society of Arts, of the fame 
City. 
This publication, which is in 4to. ac- 
companied by feventeen plates, con- 
tains an account of the fructification of 
the conferve, one of the moft obfcure 
facts in the hiftory of botany. The 
©pinions of Dillenius,. of Micheli, 
of Linnezus, of Juffieu, and of Mul- 
Jer, are all at variance upon this 
fubject. In fuch a ftate of uncertain- 
ty it became important for the perfec- 
tion of the fcience, that fomé experi- 
enced obferver fhould undertake the 
tafk of fixing the floating ideas of natu- 
ralifts, relative to the re- production of 
this plant; in order to which, it was 
neceflary that he fhould colleét the dif- 
ferent {pecies, and difcover their various 
changes, &c. Such have been the la- 
bours and employment of the authér 
whofe work is now before us. 
M. Vaucker, a few years fince, 
happening to occupy his attention with 
the cryptogamous plants, ftudied at the 
fame time the various coxferve inthe 
neighbourhood of Geneva; but al- 
though he frequently obferved them 
with a microfcope, he could never 
perceive any thing in their organiza- 
tion, that bore the moft diftant refem- 
blance to feed. A lucky accident, 
however, at laf furnifhed him withthe 
information, denied to the molt labo- 
rious inveftigations, He accordingly 
645 
publifhed a memoir in the Fournal de 
Phyfique, relative to the fructification of 
this dubious plant, and after the lapfe 
of two years, found out no less than fix 
different modes of generation. 
The plates which accompany thefe 
memoirs, reprefent the various obje&s 
as they appear through a microfcope, 
as well as when it was poflible to furvey 
them with the naked eye. 
‘© Effai fur Etude de la Mineralo- . 
gie, &c.”—An Effay on the ttudy of 
Mineralogy, as applied to France, and 
particularly to Belgium, by Rozin, 
Profeffor of Mineralogy, Botany, and 
Zoology, in the Central School of the 
Dyle, and formerly Profeffor of Natu- 
‘ral Hiftory and Chemiftry, in that of 
the Scheldt, &c. 
This littie work, confifts of a fum- 
mary of a Courfeof Mineralogy, de- 
livered in the Central School ot Bruf- 
fels. M. Doulcet de Pontecoulant, 
Prefect of the Department of the 
Dyle, having demanded an account of 
the minerals of the county and their 
fituation; M. Rozin has here detailed 
the refearches made by him, in compli- 
ance with the defire of the magiftrate 
juft alluded to. 
“ Efquiffe dune nouvelle Claffifica- 
tion de Mineralogie, é&c.’’—Sketch of 
a new Claffification of Mineralogy, fol- 
lowed by fome Remarks on the Clafiifi- 
cation of Rocks. 
This is a tranflation of a treatife, 
originally compofed by Mr. PinKER- 
TON; and Mr. JANsEN, who has here 
given a French verfion, informs us 
that he completed the greater part of 
it under the immediate infpection of 
-the author. 
" MISCELLANEOUS. 
« Du Dégré de Certitude de la Me- 
dicine, S&c.”—Of the Degree of Cer- 
tainty in Medwine; by P. J. G.Ca- 
BANIS, Member of the Confervative 
Senate, the National Inftitute, &c. a 
new. Edition,. revifed, correéted, and 
augmented, 1 vol. 8vo. 
This work, which wasthe fir produc- 
tion of Dr. Cabanis, obtained for fim 
a diftinguifhed place among the French 
profeilional writers, while his fubfe- 
quent one entitled, *‘ Sur Jes Rapports 
du Phyfique, & du Moral de l’Hom- 
me,’ in 2 vols, 8vo.—fixed his reputa= 
tion as a man of genius. 
The publication now under confiders. 
ation contains— 
I, Obfervations on Hofpitals, 
402 II. 
