Chemistry and Physies. 261 
colors, decomposing water at the ordinary temperature in the light, at- 
tacking glass feebly if at all, acting upon almost all the metals but not 
attacking gold or platina, or at least, not except in the nascent state. 
His experiments on the equivalent of fluorine, fix it at 239-81. 
finds that it presents stronger analogies with oxygen and sulphur, than 
with chlorine, bromine, and iodine, and the allied bodies. 
17. Silica, (L’ Institut, Dee. 2, 1846, No. 674.)—M. Kopp offers 
several reasons for considertng SiO? the formula of silica, instead of 
SiO’. They are based on the following considerations ;—1, the dens- 
ity and relation of volume of the compounds of silicium and bordn, as 
compared with chlorine and fluorine; 2, the density of the vapors of 
the silicic ethers; 3, analogies between silicic, titanic, and tantalic 
acids ; 4, simplicity of composition of the fluo-silicates; 5, the more 
simple formul for the most of the silicates; 6, the augmentation of the 
number of the simple and neutral silicates, adopting the formula SiO? ; 
7, diminution of the great basicity of the silicates, which seems to have 
little relation with the comparative feebleness of the acids; 8,a new 
and much more general classification of the family of feldspars. 
18. Nitrification, (L’Institut, Dec. 2, 1846, No 674.)—M. Dumas 
states that when a current of moist air containing ammonia is directed 
upon a solution of potash, the temperature being at 100° C., a quantity 
of nitrate of potash is formed through a change of the ammonia into 
nitric acid. He remarks that this experiment, which accords with the 
labors of M. Kuhlmann on nitrification, was s d to him by obser- 
vations which he had recently made upon the conversion of sulphu- 
retted hydrogen into sulphuric acid. ' 
19. Phosphate of Lime in Organic Beings, (L’Institut, Dec. 2, 1846, 
No. 674.)—M. Dumas attributes the disaggregation eran ade 
sure in the soil, and the removal of the phosphate of lime by water, to 
two causes, the one of feeble intensity and acting rarely, the other of 
first de 
gests the use of carbonated waters for persons affected with calculi of 
phosphate of lime. | 
