PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 305 
the body in question was a betaine derivative, and had the constitution 
expressed by the formula, 
Br 
(C,H). PC 
CH,—COOH, 
will be apparent from the experiments on the action of bromacetic acid on 
triethyl-phosphine (see p. 321), for the author was at first led by them to be 
lieve that no hydrobromate of the phosphorised betaine could exist. How- 
ever, the experiments just described are sufficient to establish the constitution 
of the body in question, which was further proved by the manner in which it 
decomposed when heated (see p. 316). 
Hydriodate of Triethyl-Phosphorus-Betaine.—HorMany, in the paper already 
mentioned, obtained a hemi-hydriodate of the betaine, 
| /OHs— CO 
2 fcayec mi | HI, 
on treating the free base with hydriodic acid; and Dr Crum Brown and the 
author have shown that dimethyl-thetine, when treated in the same manner, 
yields a similar compound, 
But Meyer (loc. cit.) obtained the normal hydriodate with trimethyl- 
phosphorus-betaine, viz., 
OH.) pCH,— COOH 
(CHs); se 
and could not succeed in obtaining a body analogous to Hormann’s hemi- 
hydriodate. 
The author repeated HormaAnn’s experiment (though in a somewhat modi- 
fied way). 
5 grms. of the pure hydrochlorate were converted into hydrate by the 
action of oxide of silver, and to the filtered solution hydriodic acid of constant 
boiling point was added in slight excess over the quantity required for the 
production of the normal hydriodate. The solution was evaporated to dryness 
on the water bath, and when most of the water had been driven off, yielded 
a syrupy liquid which crystallised on cooling. The solid mass was dissolved 
in alcohol and ether added. 
The hydriodate was precipitated in small granular crystals about as 
