TRANSACTIONS OF SECTION B. 965 
The following Report and Papers were read :— 
1. Report of the Committee appointed for the purpose of investigating by 
means of Photography the Ultra-Violet Spark Spectra emitted by 
Metallic Elements and their combinations under varying conditions. 
See Reports, p. 276. 
2. On the Non-existence of Gaseous Nitrous Anhydride.' By Professor 
Witiiam Ramsay, Ph.D., and J. Tupor CunDatt. 
The existence or non-existence of nitrous anhydride in the state of gas cannot 
be decided, as attempted by Lunge, by acting on it with any reagent, for that 
reagent may either decompose it or react with the products of dissociation of 
nitrous anhydride, NO and (N,0O,+NO,) as if they consisted of the anhydride 
itself. The only true criterion of the existence or non-existence of such a sub- 
stance is its vapour density. It was first conclusively proved by the author’s 
experiments that the volume of nitric peroxide when quickly mixed with nitric 
oxide does not contract, clearly showing that no immediate combination ensues. Dr. 
Lunge has previously granted the probability of this result, but says that combi- 
nation is very slow. If the combination of the products of dissociation of a 
dissociating body is slow, it must equally be the case that the dissociation of the 
dissociable substance is slow also. If this be so, the vapour density of the gas 
distilled from liquid nitrous anhydride should have a density 38, corresponding to 
the formula N,O,. A dark blue liquid having been prepared by the usual 
method, it was fractionated into a large specific gravity balloon by exhausting 
the balloon and attaching it to the bulb containing the liquid trioxide, certain 
precautions being taken to ensure that the final pressure was equal to that of the 
atmosphere. The result was that the first portion had the density of 22°35, 
while its empirical composition exactly corresponded with the formula N,O,. A 
mixture of (N,O,+NO,) with NO, in such proportion as to have the compo- 
sition N,O, should possess, from Professor W. Gibbs’ formula, the density 25-42. 
Supposing the gas thus weighed by us to have contained no N,O, but only NO + NO,, 
the percentage of N,O, necessary to be added to raise the specific gravity to 
22°35 must be 17°63. 
On analysis further fractions show a constantly decreasing percentage of 
nitrogen and a corresponding higher density. 
The argument stands thus. On mixing NO and (N,O,+NO,) no contraction 
oceurs. If combination occurs at all it must occur very slowly. On distilling a 
liquid containing N,O, the first portion of the distillate has the empirical compo- 
sition N,O,, but is proved by its density to contain at most 17°63 per cent. of N,O,, 
and this on the assumption, known to be false, that no N,O, is present in the gaseous 
mixture. These facts, combined with Dr, Lunge’s statement that the dissociation 
of nitrous anhydride is uninfluenced by rise of temperature, its behaviour thus 
being unique, in our opinion decide the point against the existence of gaseous 
nitrogen trioxide. 
3. On some Actions of a Groves’s Gas-battery. 
By Professor Wittiam Ramsay, Ph.D. 
The ordinary form of gas-battery invented by Groves consists of two tubes 
containing oxygen and hydrogen respectively, in contact with strips of platinum 
coated with spongy platinum, which dip into weak sulphuric acid. On connecting 
the terminals of the platinums outside the liquid a current is set up, and the 
hydrogen and oxygen combine to form water. But as these gases are not in 
contact, it must be conceived that at that point where the platinum is in contact 
with hydrogen and liquid, the water-molecule is decomposed, its oxygen uniting 
with the gaseous hydrogen to form a new molecule, while the hydrogen is liberated 
1 Published in full, Jowr. Chem. Soc.,1885, 672. 
