PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 327 
heating was performed with a BunseEn’s burner, the distilling flask being placed 
on wire gauze. A volatile liquid first passed over, together with about 50 cc. 
of permanent gas. The temperature of the distillate then rose rapidly to 
303° C., and the latter solidified on cooling. No more gas was evolved. 
The other half of the product was dissolved in water, and boiled with slaked 
lime* until the solution was alkaline. Only a trace of triethyl-phosphine was 
evolved. ‘The solution was then filtered, mixed with excess of dilute sulphuric 
acid, and the precipitated sulphate of calcium separated from the solution by 
squeezing the mixture on a cloth filter. The dark-brown solution thus obtained 
was distilled until its volume was reduced by about three-fourths. The colour- 
less distillate was saturated with oxide of silver, and the mixture boiled and 
filtered. 
On cooling abundance of crystalline matter separated, having the appear- 
ance of acetate of silver. It was dried in the desiccator, and a determination 
of silver made. 
0:3202 gave 02057 Ag=64'3 per cent. Ag. 
Obtained. Calculated for C,H,0,Ag. 
Silver, , : F s 64:3 ; : : : 646 
Now, in this experiment the triethyl-phosphine and bromacetic acid were 
mixed in the pure state, and the temperature was allowed to rise considerably. 
10 germs. or thereabouts of the product yielded when heated, only 50 cc. of 
gas (presumably carbonic acid) ; whereas, had the product consisted entirely of 
the betaine hydrobromate, 850 cc. of carbonic acid should have been evolved. 
Therefore only about 5 per cent. of the product consisted of the betaine hydro- 
bromate. Of what did the remaining 95 per cent. consist? The action of the 
slaked lime may, the author thinks, be considered as proving it to be the 
aceto-bromide of triethyl-phosphine— 
Br 
(C,H,) =P 
2 ake O OUCH... 
The lime acting in the same manner as caustic potash, and giving bromide and 
acetate of calcium together with oxide of triethyl-phosphine. 
Br 
ACH =P car, + UCM OW: 
5 3 
= 2(C,H,),=P = O + CaBr, + (CH,—COO),Ca + H,0. 
As before pointed out, any bromacetate of triethyl-phosphine would have been 
detected by the evolution of triethyl-phosphine on the addition of the alkali; 
whereas in this particular experiment mere traces of that body were given off. 
* Employed instead of caustic potash, on account of its insolubility. 
