Maxwell Simpson. 179 



with each other, producing hydric chloride and (C2H30)2. But 

 (C2H 3 0) 2 = C 4 H 6 02 = crotonic acid. Hence the question : is crotonic 

 acid formed when aldehyde and acetylic chloride act on each other 1 

 Wurtz had already obtained in one experiment a compound of the two 

 substances, which with water decomposed into the two components. 

 He now suggested the repetition of the experiment to Simpson, who, 

 however, could only confirm Wurtz's previous results. Experiments 

 with acetylic chloride and the aldehyde G 5 Hi produced likewise only 

 a compound of the two. 



At the conclusion of the experiments mentioned in the foregoing 

 pages, about the end of the year 1859, Simpson left Paris and retained 

 to Dublin, where, in his own house, he fitted up, in a back kitchen, a 

 little laboratory, and there, in spite of many imperfections, he carried 

 out some of his best work. 



Dumas, Malaguti and Leblanc had shown that the ammonial salts 

 of acetic-, benzoic-, valerianic-, and trichloracetic acids, by heating with 

 phosphoric acid (P 2 5 ), lose the elements of water and become converted 

 into the corresponding nitriles. And, when the nitriles are heated 

 with solutions of potassic hydrate, the corresponding ammonia salts 

 are reformed. Kolbe and Frankland observed about the same time 

 (1847) the formation of ammonic acetate by the action of potassic 

 hydrate on methylic cyanide, and of ammonic propionate by a similar 

 metamorphosis of ethylic cyanide. In these changes only monovalent 

 radicals took part. Simpson undertook to investigate the behaviour of 

 cyanides of divalent and trivalent compound radicals with hot solutions 

 of potassic hydrate. He commenced with ethylenic cyanide ; the result 

 was the potassium salt of ordinary succinic acid. 



C 2 H 4 Br 2 *- C 2 H 4 Cy 2 -* C 2 H 4 (C0 2 H) 2 



("P.," x, 574, xi, 190). Ethylidenic cyanide submitted to the same 

 treatment was expected to yield potassic isosuccinate. Instead of this 

 the common succinate was obtained. Propylenic cyanide and potassic 

 hydrate solution produced potassic pyrotartrate : 



The structure of the members of the oxalic acid series was made clear by these 

 results. Allylic tricyanide boiled with potassic hydrate gave Simpson 

 the potassium salt of tricarballylic acid : 



(" P.," xii, 236). This acid, which is related to aconitic acid as propionic 

 is to acrylic acid, was first obtained by Dessaignes in impure condition 

 by the action of sodium amalgam on aconitic acid. Kekule suggested 



