310 PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 
Ethyl-Bromate of Triethyl-Phosphorus-Betaine.—Bromacetic ether acts on 
triethyl-phosphine with even greater energy than chloracetic ether. It is 
necessary to dilute the bromacetic ether with dry ether before adding the 
phosphine, otherwise so much heat is disengaged that the compound is par- 
tially decomposed. 
Each drop of the phosphine occasions a turbidity in the solution, and the 
ether boils from the heat disengaged unless the vessel in which the experiment 
is conducted is placed in cold water. A layer of oily liquid soon forms, and 
after a few minutes this suddenly solidifies to a solid crystalline mass, whilst 
the supernatant ether also deposits abundance of crystalline matter. Owing 
to the extreme deliquescence of this body, its analysis was not attempted. Its 
reactions, however, leave no doubt as to its composition and constitution, 
which are expressed by the formula, 
Br 
(CsH)=PK 
CH,—CO0C,H,. 
This is of some importance, for, as will be shown presently, bromacetic acid 
does not, except under special conditions, give a betaine derivative with triethyl- 
phosphine. 
Ethyl-Iodate of Triethyl-Phosphorus-Betaine.—Iodacetic ether and triethyl- 
phosphine react on each other with as much energy as bromacetic ether and 
the phosphine, and dilution with ether is necessary to moderate the action. 
Exactly the same phenomena are observed as in the preparation of the ethyl- 
bromate. On mixing the ethereal solution of the iodacetic ether with the 
phosphine an oily layer is precipitated, which solidifies after a short time. 
The compound was not analysed. 
Action of Heat on the Compounds of Triethyl-Phosphorus-Betaine. 
One of the most interesting questions which presented itself in connection 
with the compounds which have just been described, was the change which 
they would suffer when submitted to the action of heat. Indeed, the author 
was chiefly induced to study them from a desire to decide this question. 
For he had shown some time ago* that the compounds of dimethyl-thetine 
are decomposed by heat in a very interesting way, and from the analogy of 
these bodies with corresponding compounds of the phosphorus-betaine, he was 
strongly inclined to the belief that the latter would behave in a similar manner 
to the former when heated. 
The interest of the question was considerably heightened by the fact that 
* Lurts, These Transactions, vo]. xxviii. p. 591, 
