[201 J 
FRENCH NATIONAL INSTITUTE. 
In the public fitting of Vendemiaire 15, An. 7, the fol- 
Jowing notice of the labours of the different claffes was read 
by the fecretaries of each clafs : 
PHYSICAL SCIENCES. 
The experiment of the reduction of lead by fulphur have 
ing been announced by Wiegleb, a German chemift, as 
favourable to Stahl’s theory of phlogifton, Citizen Guytom 
fhewed that this experiment is not conclufive, if an appas 
ratus be ufed that permits the operator to keep an account 
of all the agriform fluids, The fame chemift made experi- 
ments on the nature of the fuccinic acid and the produéts 
from its decompofition. From his experiments he is inclined 
to aflign to that foflil a vegetable origin, which agrees with 
the obfervations of mineralogifis. Citizen Guyton alfo 
laid before the clafs the produéts of his experiments on uri- 
nary concretions, which, as Scheele announced, manifeft 
the prefence of a peculiar acid formed in thefe. concretions. 
New obfervations on the yellow colour that, may. be ex- 
tracted from vegetables for the art of dyeing, were commu- 
nicated by Cit. Chaptal.. (See Pdil: Mag. Vol. I. p.430:) 
The fame chemift {hewed that the difference between. the 
acetous and the acetic acid confifts in the proportions of 
carbon, which is the radical; and that the -acetous acid con- 
tains much more than the acetic, 
_ A heavy greyith ftone of a clofe texture, found fome years 
ago in the quarries of Menil-Montant, near Paris,.and 
which had been confidered for fome time as fulphat of ba- 
rytes and afterwards as fulphat of lime, was analyfed. by 
Citizen Vauquelin. It appears to be a compound of the 
fulphat, of ftrontian and the carbonat of lime. 
The fame chemift prefented two procefles for the fetiaries 
tion of the component parts of brafs by the wet way. . The 
— 
firft confifts in diilolying in the nitric acid a determinate | 
quantity 
