114 Scientific Intelligence. 
Phosphate, . . ‘ : P-(Hg).0, 
Phosphovinate, ‘ ‘ ‘ - (a3 C, H, O) O, 3 
Phosphodivinate, . . ‘ H, 2C, H. , 0) O,4 
Phosphotrivinid, : ‘ ‘ P (ac, H. 0) O, ae 
On the Estimation of Nitrous acid; by H. Rae Lae ee 
Annalen, April, 1849.)— ‘This process is founded on the decomposition 
of urea by nitrous acid into carbonic acid and nitrogen, noticed by 
Millon, and so by him in the estimation of urea. (See this 
our., vol. v -) 
The well wok ane twin flask apparatus of Will and Fresenius is used ; 
in one flask sulphuric acid is employed as usual—in the other a solu: 
tion of urea and the nitrite to be analyzed. The apparatus is weighed, 
sulphuric acid is drawn over, and when the reaction is finished, a suffi- 
cient quantity of air is passed through the flasks, and a second weighing 
gives the loss of CO, and N. A loss of 1:00 answers to “76 of nitrous 
acid. G. C. ScHAFFER. 
5. New mode of preparing Nitrogen; by B. Cornenwinper.—(Ann. 
de Chim. et de Phys., July, 1849.)—No former process for obtaining 
pure nitrogen is both easy and expeditious. The author employs t 
remarkable decomposition of nitrite of ammonia by heat, into nitrogen 
and water—but instead of the salt formally prepared, he makes use of 
solution of nitrite of potash and parca nines of ammonia. Through 
a solution of caustic potash, sp. gr. 1°28, is passed nitrous gas (obtain- 
ed from the reaction of starch 1 pt. and “—_ acid 10 pts.) uotil the 
product is acid, the solution is then made alkaline by caustic potash, 
and may be preserved in this state without change. ‘To prepare nitro- 
gen, add to 1 vol. of this solution 3 vols. of very strong solution of hy- 
drochlorate of ammonia, and heat moderately in a small flask—the gas 
is disengaged very soon, and the decomposition goes on very regularly. 
To remove the small quantity of ammonia set free by the slight excess 
of caustic potash, the gas must be passed through water acidulated with 
sulphuric acid. The nitrogen thus obtained is said to be perfectly pure. 
An economical substitute for the solution of the nitrite prepared 
as described above, would be found in the nitrite of potash obtained 
by cautiously heating nitre—in this case there would be sufficient excess 
of alkali to ensure the stability of the salt in solution. | G.C. 
ew — for detecting — and Bromine ; by M. A. Rey- 
so.—(Comptes Rendus, April, 1849.)—To ie ‘the well known 
difficulties i in the use of chlorine, it is proposed to employ peroxyd of 
hydrogen to set free the iodine or bromine. A fragment of binoxyd 
of barium is put into atest tube, and water, hydrochloric acid and 
starch paste are added—when we wish to test for iodine, as soon as bub- 
bles arise, the liquid to be tested is poured in. In testing for bromine, 
ether must be substituted for starch paste, 
When sulphurets, sulphites, or hyposulphites are present, on account 
of the absorption of oxygen to form sulphates, &c., more than the 
usual quantity of peroxyd of hydrogen is required. The sulphate of 
baryta for retards the action unless the mixture is agitated, and in 
fact it is better ia all cases to do so to hasten the evolution of the peroxyd 
of hydrogen. This process is said to indicate — e of less than 
1 part of iodide of potassium in 100,000 of w G.C 
a 
