36 Dr. ET. Collie on the Action of Heat on 



some substance boiling between 200°-220° C. It did not 

 seem to be attacked when boiled with strong caustic potash, 

 but traces of acetate of potash were detected in the aqueous 

 solution. It was not changed by hydrochloric acid, and had 

 a pleasant aromatic smell. It gave a crystalline compound 

 with bisulphite of sodium, and on oxidation with chromic acid 

 a mixture of acetic and benzoic acids was produced. The 

 substance is evidently therefore the methylbenzylketone, 

 b.p. 215° C; and probably mixed with it is a trace of the 

 acetate of benzyl, which gives the acetate of potash when 

 boiled with caustic potash. The chief decomposition which 

 the acetate undergoes when heated is therefore as follows : — 



(C 2 H 5 )P^ = (C 2 H 5 ) 3 PO + CH 3 .CO.C 7 H 7 ; 



\)-j-COCH 3 



while a small quantity of the salt splits up, yielding triethyl- 

 phosphine and the acetate of benzyl, 



(C 2 H 5 ) 3 (C 7 H 7 )P. . COCH 3 = (C 2 H 5 ) 3 P + C 7 H 7 . COCH 3 . 



Oxalate of Triethylbenzylpliosphonium. 



When the chloride of triethylbenzylpliosphonium is treated 

 with oxalate of silver, this salt is produced, together with the 

 chloride of silver. The insoluble silver salts were separated 

 by filtration, and the solution of the oxalate concentrated to 

 a small bulk over the water-bath. During the evaporation a 

 slight smell of the diethylbenzylphosphine was noticed, and 

 the solution, which had been neutral, became slightly acid in 

 its reaction with litmus paper. The concentrated solution, 

 when allowed to stand over sulphuric acid in vacuo, soon 

 solidified to a mass of radiating crystals. Eight grams of 

 these were subjected to the action of heat. Decomposition 

 began at 170° C, and gas was rapidly evolved; the tem- 

 perature was gradually raised to 250° C, when the whole of 

 the salt had distilled, and no charring had occurred. 



The distillate was completely composed of toluene and oxide 

 of triethylphosphine, and not a trnce of any other substance 

 could be detected. The gases evolved were first treated with 

 caustic potash solution, when about one half dissolved ; the 

 remainder was not attacked by bromine; it burnt with a blue 

 flame, and gave carbon dioxide alone when exploded with 

 oxygen gas. 



It is difficult to explain the formation of only toluene and 

 oxide of triethylphosphine, and the absence of triethylphos- 

 phine, unless water has taken part in the reaction. 



