1816.] Royal Institute of France. 391 
the sea; while at the same time, from the magnitude and extent of 
the surface, and other occult causes, we are not aware of the eleva- 
tion of its level in any sensible degree. That Almighty Being who 
hath said, “ Hitherto shalt thou come, and no iurther,” has, with 
infinite wisdom, created a kind of compensating power to counter- 
balance the seeming conflict. of the elements of earth and water ; 
for while the ocean appears to be extending its surface, it seems also 
bable that the quantity of its waters upon the whole are lessened, 
that part of them undergoes a complete and permanent change of 
form after the process of evaporation ; and that the earthy particles 
continually accumulating, at least to a certain depth, at the bottom 
of the sea, have a direct tendency not only to preserve an uniform 
level, but even in some instances to make the water overrun what 
we have been accustomed to consider its boundary. 
March 16.—There was read an interesting memoir of the late 
Dr. Walker, Professor of Natural History in the University of 
Edinburgh, containing an account of his mineralogical studies, and 
of his systematic arrangement of minerals. 
= 
ROYAL INSTITUTE OF FRANCE, 
Account of the Labours of the Class of Mathematical and Physical 
Sciences of the Royal Institute of France during the Year 1815. 
Puysicat Department.—By M. le Chevalier Cuvier, Perpetual 
Secretary. 
(Continued from p. 315.) 
Borany. 
M. Delabillardiere, who has already published so interesting a 
work on the plants which he collected in New Holland, when he 
accompanied the late Hntrecasteaux in his expedition, has begun to 
give an account to the Class of those which he found in New Cale- 
donia. ‘This steep island, uncultivated as it is, and inhabited by 
unhappy cannibals, produces a great number of fine plants. M. 
Delabillardiere found in a few days 29 new species of fern, 12 of 
which are entirely new to the botanist, and have been found no- 
where else. The others grow likewise in the other islands of the 
South Sea; and M. Delabillardiere gives a list of them, to eluci- 
date geographical botany. He arranges these ferns according to the 
method of Dr. Smith, making some corrections in it. The ve 
accurate figures with which his descriptions are accompanied will 
give to botanists a complete idea of these important additions to 
their science. 
_ Every person is acquainted with the aquatic plant called duck= 
meat, and by botanists lemna. ‘This moveable and swimming 
vegetable covers with its green foliage the stagnant waters of almost 
