■ 234_ Proceedings of the Royal Society 
Its solubilities were carefully ascertained, and it was found to be 
very slightly soluble in water ; largely soluble in ethylic alcohol, but 
much more soluble in methylic alcohol or methylated spirit ; and 
soluble in every proportion in ether, chloroform, glacial acetic acid, 
and carbolic acid ; freely soluble in benzol ; difficultly soluble in 
carbon disulphide ; and practically insoluble in glycerine. 
On account of the constancy observed in the amount of nitrous 
acid produced when nitroglycerine is decomposed by an alkali, the 
author suggests a method for estimating nitroglycerine by decom- 
posing it with potash or soda in alcoholic solution, and afterwards 
determining the amount of nitrous acid by means of starch and an 
iodide. 
10. The Elementary Composition of Nitroglycerine. By 
Matthew Hay, M.D., and Orme Masson, M.A., B.Sc. 
Communicated by Professor Crum Brown. 
(A full report of this paper appears in the Transactions of the Society.) 
Investigations have been made by Railton, Williamson, Hess and 
Schwab, Beckerhinn, and Sauer and Ador for the purpose of ascer- 
taining the elementary composition and the constitution of nitro- 
glycerine. They all agree in regarding it as a nitrate of glyceryl ; 
but, whilst some consider that it is a tri-nitrate, others hold that it 
is a variable mixture of the tri-nitrate with di-nitrate and mono- 
nitrate. Their analyses are quite insufficient to establish either the 
one or the other conclusion, and have mainly been confined to 
estimations of the nitrogen. If we except a comparative estimation 
of the carbon with the nitrogen, there exist absolutely no determina- 
tions of the carbon or of the hydrogen. And, as the decomposi- 
tion of nitroglycerine with potash has been shown to occur in a 
manner considerably different from that suggested by Railton and 
Williamson, the main reason in support of the constitution of nitro- 
glycerine as a tri-nitrate has been removed.* The authors of the 
present communication therefore believed that they were amply 
justified in making a fresh and more careful and complete analysis 
of the composition of nitroglycerine. Absolute determinations 
were made, not only of the nitrogen, but also of the carbon and 
* Vide preceding paper by Matthew Hay. 
