1816} Royal Institute of France. 229 
bruary, a paper was read by Robert Brown, Esq. Librarian to the 
society, containing general observations on the tribe of plants called 
Coinpositee. ‘This paper contained many curious remarks upon the 
structure of the flowers of this difficult tribe of plants, marked by 
' the precision and sagacity which characterize all the papers of this 
acute observer ; but of so miscellaneous a nature that it is scarcely 
possible to give any abstract of it without transgressing our usual 
limits. 
——S 
ROYAL INSTITUTE OF FRANCE, 
Avcount of the Lalours of the Class of Mathematical and Physicaé 
Sciences of the Royal Institute of France during the Year 1815, 
Puysicat DepartmEent.—By M. le Chevalier Cuvier, Perpetuat 
Secretary. 
Another year of devastation and terror! The bloody discord of our 
new country, the existence of this fine kingdom brought into doubt, 
the repose and the fortune of the most peaceable citizens for some 
time without protection or security; innumerable armies inundating 
our provinces, taking possession of our towns, seizing by violence 
in the midst of a conquered capital those treasures of the arts for- 
merly collected in a manner equally violent. Such, to the most 
innocent, have been the consequences of a too culpable attempt. 
But tlie sciences bring with them a state of consolation and 'tran- 
quillity. At present all nations respect them. In the midst of the 
tumult of arms, our Archimedes have nothing to fear from en- 
lightened soldiers, to whom their names and their labours are 
known, and who rejoice to become for a short time their disciples. 
It is perhaps even in the most terrible moments that, taking refuge 
in profound meditation, emancipating themselves by the exaltation 
of their minds from the horrors that surround them, they have made 
some of the most fortunate combinations, and some of the most 
fruitful discoveries. We shall find, at least, that the list of the 
laboars of this year is not inferior to that of the most peaceable 
time. 
CuEmisTry. 
We have been speaking for two years of those acids without 
oxygen, or, as they are now called, hydracids, which have made so 
considerable a breach in the imposing chemical edifice of Lavoisier. 
The labours of Gay-Lussac have shown this year that there is one 
more to add to this class—the acid called prussic by M. de Morveau, 
because it enters into the composition of Prussian blue; and its 
radical not being then known, it was mot possible to give it a name 
from that substance. 
The experiments of Margraaf, Bergman, and Scheele, demon- 
strated that in Prussian blue the iron was united to a substance 
Which acted the part of an acid. Serthollet had long suspected 
‘that no oxygen entered into its composition, but merely carbon, 
