PREP Se en 
ees 
Si 
Chemistry. 113 
ed along wich the precy: long to cool, mene - wart — 
and eee 
ener. , furnishes aq 
and super-satur 
is but slightly sohibly in cold water and insoluble i in alcohol and ets 
Its composition is C16NH®O5. It is soluble in the alkalies, and com- 
bines with acids. If the fused caseine and potash be treated with tar- 
taric instead of acetic acid, and the liquid’ submitted to distillation, it 
furnishes valerianic acid. This acid appears to be preceded in its forma- 
tion by leucine, which substance is itself converted in to valerianic acid 
ee the action of potash. 
10. Bromo-boracic Acid, (Bromide of Boron;) by M. Pools, 
dni fe Rendus, Jan. 1846.)—It is prepared by passing the vapor of 
bromine through a mixture of charcoal and boracic acid, heated to red- 
ness in a porcelain tube. It is well to heat the mixture of charcoal and 
boracic acid for about half an hour previous to passing the vapor of 
bromine through it, in order to get rid of any moisture. The acid, 
which is a gas, can be collected over mercury, this metal absorbing 
any excess»of bromine. It is a colorless gas with a pungent odor 
and acid taste ; it extinguishes combustion and affords white vapors in 
contact with the air. Chlorine decomposes it with the liberation of bro- 
mine. Its density is 86443, and its composition is BBr*, J. L. 8. 
‘11. Quantitative estimation of Bromine in Mineral Waters; by 
M. Heine, (Journ. fiir Prakt. Chem., xxxvi, 181, and Chem. Gazet., 
March, 1846, p. 103.)—A series of liquids containing a known amount 
of bromine is prepared, by dissolving in every ounce of distilled water 
from five to fifty milligrammes of bromide of potassium, making a series 
of ten liquids. Equal quantities of ether, measured in the same glass, 
are added to these different solutions and the tubes immediately closed. 
An equal quantity of chlorine water is next added to the solutions and 
the mixture well shaken. Upon allowing it to rest, the ether collects on 
the surface, holding in solution the bromine, and we thus obtain a regu- 
lar scale of colors, from yellow to brown, and these solutions now serve 
as standards of comparison. Beyond fifty the comparision becomes 
more uncertain, because the tints of every additional five milligrammes 
of bromide of potassium can no longer be well distinguished, on ac- 
count of the dark color.’ Five milligrammes of bromide of ergo 
is equal to 3:3 milligrammes of bromide. — 
As soon as the scale of colors has been piped an ounce of the 
liquid to be examined, is introduced into’a vessel similar to the ones con- 
taining the test solutions, and to it is added the same amount of chlorine 
and ether as in the other cases, it is shaken, and the ether allowed to 
collect upon the surface, the color of which, by comparison with the 
Scale colors, will indicate the amount of isd present. J. L.S, 
Sxcosp Srnigs, Vol. II, No. 4.—J uly 1846. 
