112 Proceedings of the Royal Society 
At the present stage of my researches it would be premature to 
express an opinion on the nature of the substance produced, when 
haemoglobin is acted upon by nitrites and nitrous acid. That it 
holds a very close relation, indeed, to 0 - haemoglobin, with which 
it appears to be isomorphous, is obvious, whilst it is most im- 
probable that it has any analogy to the bodies formed when blood- 
colouring matter is treated with carbonic oxide, or when subjected 
to the prolonged action of nitric oxide, in the presence of ammonia. 
When CO acts upon blood, or, as Hermann has recently shown, 
when NO is made for a long time to pass through blood made 
alkaline with ammonia, there are formed compounds in which one 
volume of CO or one volume of NO have respectively replaced one 
volume of oxygen in the colouring matter — compounds which present 
exactly the same spectrum as ordinary blood, but which differ from 
it in being totally irreducible. That N 2 Cb should form a compound 
of this character seems improbable, and that NO should form two 
altogether distinct compounds with blood-colouring matter, is even 
more improbable. It is, however, much more likely that the action 
of nitrites and nitrous acid is mainly a reducing action, and that 
the body obtained by me is merely a less oxygenised form of blood- 
colouring matter. 
4. Antiquities, Scenery, &c , of Cambodia, illustrated by a 
series of Photographs, shown by the Oxyhydrogen Light. 
By J. Thomson, Esq., F.B.G-.S. Communicated by Pro- 
fessor Sir J. Y. Simpson, Bart. 
The following Gentlemen were elected Fellows of the 
Society : — 
James Donaldson, LL.D. 
James Richardson, Esq. 
The following Donations to the Library were announced : — 
Transactions of the Linnean Society of London. Yol. XXY. 
Part 3. 4to . — From the Society. 
List of the Linnean Society of London for 1866. 8vo . — From the 
