318 PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 
however, proposes to make other experiments with the view to obtaining it, 
although he thinks it very possible it is not capable of existence. 
Amongst the experiments made in this direction, may be mentioned one in 
which alcohol was heated for more than a week in a sealed tube with the 
hydrochlorate of triethyl-phosphorus-betaine at a temperature varying from 
90°-100° C. Now the hydrobromate of dimethyl-thetine when heated with 
alcohol gives thio-diglycollic ether. Thus-—- 
CH, 
2 (CHSC 
T 
The phosphorised betaine compound was however simply decomposed, even 
at the temperature mentioned, into carbonic anhydride and chloride of triethyl- 
methyl-phosphonium. 
—COOH 
+ 2C,H,O = S(CH,COOC,H,), + (CH,),8+2CH,Br+2H,0. 
Action of Caustic Potash on Compounds of Triethyl-Phosphorus-Betaine. 
The author was led to these experiments by an observation he had made, 
that the product of action of bromacetic acid on triethyl-phosphine is readily 
acted on by caustic potash, with formation of oxide of triethyl-phosphine. 
The author was aware that bromacetic acid and triethyl-phosphine do not, 
except under special conditions, givé a betaine derivative ; the product formed 
by their union being of a different nature. 
It occurred to him that caustic potash might, however, react with a 
compound of the phosphorised betaine so as to give oxide of triethyl-phosphine, 
and he deemed it of importance to decide this point by experiment. 
Action of Potash on the Hydrochlorate.—A preliminary experiment showed 
that an oily layer at once separated when strong potash solution was mixed with 
the hydrochlorate. 
13 gms. of hydrochlorate (once recrystallised) were dissolved in about 25 ce. 
of water, and solid potash added by degrees. The solution grew very hot, and 
developed a faint odour of triethyl-phosphine, which the author believes to 
have been due to impurities present in the hydrochlorate. When 18 grms. of 
potash had been added, the solution separated into two layers, the lower of 
which consisted of an aqueous solution of the salts formed by the reaction. 
The upper layer was of a yellow colour. It was separated in a tap funnel, and 
fractionally distilled. The thermometer rose rapidly, and remained stationary 
within a degree or two of 240° C., during which a colourless distillate passed 
over, which solidified to a crystalline mass on cooling. 
The boiling-point, zinc iodide compound, and other properties of this body, 
at once characterised it as oxide of triethyl-phosphine. 
It should have been mentioned, that before all the potash had been added 
