MarcH 15, 1912] 
nitric Acid and its Salts. II. The Action of 
Copper and of Cuprous Oxide on Hydronitric 
Acid. 
In order to test the plausibility of certain reac- 
tions proposed to account for the phenomena ob- 
served at magnesium, aluminium and zine anodes 
in sodium trinitride solution, reactions analogous 
to those hypothesized were induced and the ac- 
companying phenomena were examined. The ac- 
tion of cuprous oxide on hydronitrie acid is that 
of a reducing agent, the acid being reduced to 
ammonia and free nitrogen and the cuprous oxide 
becoming cupric trinitride. The relations here 
existing may be represented qualitatively by the 
expression: Cu.O + 5HN,= 2CuN, + H.O + NH, 
-+N;. With metallic copper, cupric trinitride re- 
sults, and ammonia and gaseous nitrogen again 
appear as the reduction products. To represent 
this reaction, the equation is given: 
Cu + 4HN; = CuN, + NH,N, + N:. 
J. W. TURRENTINE and LEONARD A. MAYNARD: 
The Reduction of Hydronitric Acid by Cadmium. 
Hydronitrie acid dissolves cadmium with effer- 
vescence. A neutral solution of cadmium trinitride 
and ammonium trinitride results. The gas evolved 
is nitrogen. The following equation is proposed 
to represent the course of the reaction: 
Cd + 4HN, = CaN, + NHN, + N;. 
The products of the reaction have been measured. 
In the reactions with cuprous oxide, copper and 
cadmium (and with numerous other substances), 
hydronitrie acid is found to be an oxidizing agent, 
an analogue of nitrie acid, a fact which leads to 
an analogous structure. Accordingly, the struc- 
tural formula for hydronitric acid, H—N=N—N, 
is proposed, analogous to that of nitric acid, 
H—O-N=o- 
This structure is supported by numerous reactions 
and considerations yet to be presented. Just as 
nitric acid is regarded as a hydrated oxide of 
nitrogen, hydronitric acid may be considered an 
ammoniated nitride of nitrogen. 
E. H. ArcHipaup: The Hydrolysis of Potassium 
Chloroplatinate. 
The hydrolytic decomposition of solutions of 
potassium chloroplatinate at a temperature of 25° 
has been studied. The hydrolysis can be followed 
by titrating the hydrochloric acid formed with 
sodium hydroxide, using phenolphthalein as indi- 
eator. 
SCIENCE 
431 
The hydrolysis takes place very rapidly under 
the influence of light, apparently the ultra-violet 
rays only being concerned, as no action is caused 
by the strongest illumination from four Welsbach 
mantles. In bright sunlight at a temperature of 
25° the reaction is complete in the case of a N/50 
solution in 200 minutes when an amount of hydro- 
chlorie acid will have been formed equivalent to 
36.5 per cent. of the chlorine present as platinum 
tetrachloride. A solution of this strength pre- 
pared in non-actinie light and kept in the dark 
has not attained equilibrium before several weeks. 
In the case of a hundredth normal solution the 
time required for equilibrium to be established in 
bright sunlight is 175 minutes and hydrochloric 
acid is formed corresponding to 50 per cent. of 
the chlorine present as platinum tetrachloride. 
The reaction reverses to a small extent when the 
solution hydrolyzed by the bright sunlight is 
placed in the dark. 
The reaction reverses much further, rapidly in 
the light but very slowly in the dark, when potas- 
sium chloride is added to the hydrolyzed solution. 
E. H. ARCHIBALD and HE. F. Conway: The Hy- 
drolysis of Potassium Bromoplatinate. 
The hydrolysis of potassium bromoplatinate has 
been studied after the manner of the previous 
investigation. The source of the ultra-violet rays 
was in this case an electric are placed about 25 em. 
from the solution to be studied. The temperature 
was kept constant at 25°. The hydrolysis is more 
complete than in the case of the chloroplatinate; 
the amount of hydrobromic acid formed in a 
N/100 solution corresponded to 78 per cent. of the 
bromine present as platinum tetrabromide. The 
reverse reaction also goes further when the hy- 
drolyzed solution is placed in the dark. 
A solution of the bromoplatinate prepared in the 
absence of actinic rays and kept in the dark 
showed no detectable hydrolysis after five days. 
H. C. Cooprr, E. H. Kraus and A. A. KLEIN: 
Lead Silicates. 
Having subjected the system PbO—SiO, to 
thermal analysis and optical analysis, the latter 
particularly difficult because the refractive indices 
of most of the lead compounds are higher than the 
index of any known immersion liquid, the authors 
conelude that PbSiO;, Pb.SiO, and Pb,Si,0, are 
well-defined compounds and that Pb,SiO, is prob- 
ably also an independent substance. The minerals 
barysilite, found in Sweden by Sjogren and Lund- 
strom and the mineral alamosite, recently de- 
scribed independently by Palache, correspond fully 
