French National Institute. 155. 
M. Sage has also taken a part in these experiments, with 
the intent to colour glass red by means of copper and the 
phosphate of lime, or with bones; and he has shown cry- 
stals of glass, from the bottom of the pots used to melt 
glass in the bottle-manufacture at Seyes, which had some 
resemblance to hexaédral prisms.—It is well known that 
simple means have been discovered to extract soda from 
common salt. France formerly imported this article, so 
necessary to the arts: an inconvenience attended the mode 
of preparing it, from the quantity of acid gas which escaped, 
and was highly injurious. Amongst the différent means 
of preventing this inconvenience which have been attempted, 
that of M. Pelletan the younger is deserving of notice. It 
consists in making the muriatic acid gas pass through long 
horizontal tubes partly filled with calcareous earth, which 
absorbs the gas, forming with it the muriate of lime. The 
experiments of M. Sage on plumbago (black lead) show that 
this substance does not contain any iron, but consists of a 
coaly matter mixed with one-tenth part of clay. The fossil 
carbon of St. Symphorien, near Lyons, approaches nearer 
to this substance than any other known mineral. 
M. Deyeux has presented to the class of agriculture a 
loaf of sugar made from the red beet (letterave), which had 
all. the whiteness and flavour of sugar from the cane. He 
has announced that this substance may be made in great 
quantities by the proprietors, who have devoted to this at- 
tempt 400 acres of ground. | Should it succeed on the great 
scale, it will change the relations of the two worlds. 
M. Desaaignes, principal of the college of Vendome, has 
continued his experiments on the different causes which 
produce Juminons appearances; whether spontaneous, by 
triction, or gentle warmth, and in every other circumstance 
different from that of combustion. This philosopher ob- 
tained the prize on the same subject the last year: his pre- 
sent researches have considerably enlarged the results of his 
former experiments. In general, it has appeared to M. Des- 
_ Saignes, that those bodies are the most phosphorescent that 
contain in their composition principles which can pass from 
a state of gas or liquid to a solid form. All bodies give 
‘out light by compression, whether they are fluid, solid, or 
gascons. He has also discovered that points have the same 
effect on phosphorescence as upon the electric fluid. 
M. Dessaignes distinguishes two kinds of phosphorescence ; 
the one transient, the other permanent. Amongst the first, 
we may state that which takes place when a certain quan- 
tity of water combines with quicklime ; amongst the latter, 
that of rotten wood, and other organized substances in a 
state 
