68 DR MATTHEW KAY ON THE 



glyceryl ; and hence the nature of its physiological action. Some estimations, 

 however, of the quantity of the nitrous acid proved to me that whilst the larger 

 portion of the nitrogen of the nitroglycerine appeared as nitrous acid in the 

 decomposed products, yet a considerable portion was present in some other 

 form. 



The production of a large amount of an alkaline nitrite, when nitroglycerine 

 is decomposed by an alkali, is a fact which, very strangely, has hitherto 

 escaped the observation of chemists. Muller and De la Rue * have, indeed, 

 remarked the formation of nitrous acid in the spontaneous decomposition of 

 badly-washed nitroglycerine ; and Hess and Schwab t have even stated that 

 nitrite of potassium is formed in addition to nitrate of potassium when potash 

 is allowed to act on nitroglycerine, but they appear to have believed that the 

 nitrite was formed in small quantity, and was quite a subsidiary product of the 

 decomposition. Ever since Railton,J in 1855, published his paper on " Nitro- 

 glycerine and its Products of Decomposition by Caustic Potash," the 

 decomposition has been invariably represented, and even in the most recent 

 works on chemistry, by the equation: — C 3 H 5 .3^0.N0 2 ) + 3HKOH=:C3H 5 

 .30H + 3(KO.N0 3 ) ; that is, caustic potash decomposes nitroglycerine with 

 the formation of glycerine and nitrate of potash ; and it is mainly from the 

 supposed correctness of this equation that the formula for the constitution of 

 nitroglycerine has been derived. Williamson,^ in the following 3 r ear, gives 

 an account of an investigation of nitroglycerine, and with results so exactly 

 similar, even in detail, to those of Railton, that it is apparent that these 

 chemists had made the investigation conjointly, although they published their 

 results separately. Railton supplies a more minute account of his method of 

 analysis of the products of decomposition, and it is not difficult to understand, 

 from a careful perusal of it, how he was led to suppose that the nitrate of 

 potash, which he obtained by crystallisation, was the only salt present. He 

 applied no tests for nitrous acid, and he made no quantitative estimation 

 either of the nitrate of potash or of the glycerine ; and I may anticipate some 

 of the results of the present investigation, and say that it is highly improbable 

 that he obtained any glycerine at all, as he probably mistook for glycerine a 

 syrupy residue consisting of other substances. No succeeding investigator of 

 the chemistry of nitroglycerine has examined much more minutely the decom- 

 position products ; and the equation, therefore, remains as yet unaltered. It is 

 evident that the constitution of nitroglycerine and the action of alkalies on 

 nitroglycerine afford room for further investigation. 



* Muller und De la Rue, Liebicfs Annalen. d. Gkewie., CIX. 122. 



f Hesh und Schwab, Berichte d. deutsch. chem. GesdUchft. Bd. XT. (1878), S. 192. ' 



\ Railton, Qu. Journ. of Chem. Soc, vol. vii. p. 222. 



§ "Williamson, Pro'-. Roy. Soc. Lond., vol. vii. p. 130. 



