Mr. A. B. Northcote on Parathionic Acid, 219 



liar interest from the researches of Wurtz, Kekule, Boutlerow, 

 and others ; and the difference of molecular grouping has been 

 clearly manifested, although much light .has not yet been thrown 

 on its cause or even its manner. Great part of the work thus 

 accomplished lies within the limits of the alcohol series ; and the 

 production by Wurtz, Boutlerow, and Friedel respectively of iso- 

 mers of the amyle and propyle alcohols lends a powerful aid to the 

 observations which have been made in the same series with regard 

 to the sulphovinic acids. 



Hennel* in 1826 proved that sulphethylic acid was produced 

 when defiant gas was absorbed by oil of vitriol; and Berthelot 

 in 1855 found that when the sulphethylic acid obtained by this 

 means was saturated by carbonate of barium, ordinary sulphethy- 

 late of barium was not the product, but that far more stable 

 isomeric barium salt, the acid of which Gerhardt had already 

 shown to result from the decomposition of the ordinary sulph- 

 ethylate of barium by the boiling of its aqueous solution, and to 

 which he had applied the name of Parathionic acid. 



A parallel instance to this isomer in the sulphethylic series 

 has been found by Church f in the sulphomethylic. He has 

 shown that in the decomposition of sulphomethylate of barium 

 by water an acid is obtained, the barium salt of which is stable 

 at the temperature of its boiling aqueous solution, bearing thus 

 the same relation to ordinary sulphomethylate of barium as Ger- 

 hardt's parathionate does to the sulphethylate of barium. This 

 result he attributes to the intermediate production of sulphate of 

 methyle, decomposible by water, supporting his conclusion upon 

 an observation made on the decomposing influence exerted by 

 water upon the sulphate of ethyle- methyle, in which change both 

 the alcohols and both the modified acids are produced. 



The conditioDS under which I have encountered what I can 

 have but little doubt is the same isomer are different from these. 

 I had prepared a solution of potash in pure absolute alcohol at 

 least five years ago, since which time it had remained in a well- 

 stoppered bottle : it had become but little carbonated or changed 

 in appearance from its original early darkening of colour. While 

 recently preparing the sulphovinic acid of a wax-alcohol, I had 

 occasion to employ this specimen of potash for the neutralization 

 of the sulphuric acid in which the wax-alcohol had been dissolved ; 

 more alcohol was added and then the potash. In the mass of 

 sulphate of potassium which separated was found the sulphovi- 

 nate I was seeking to prepare ; but the clear alcoholic filtrate in 

 which nothing was suspected to exist, left, when its alcohol was 

 distilled off, a small quantity of a salt which, after two crystalli- 



* Gmelin (Cav. Soc), vol. viii. pp. 168, 416. 

 t Pbil. Mag. July 1855 and January 1856. 



