PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 301 
on bromacetic acid, ashe had employed the latter reagent in his experiments on 
the thetines. Instead, however, of obtaining the hydrobromate of triethyl-phos- 
phorus betaine by this reaction, other bodies were formed, the investigation of 
which was extremely troublesome, and lasted over a considerable time. 
It was only when he substituted chloracetic for bromacetic acid that he 
obtained betaine compounds, and then the investigation was much simplified. 
The author thinks it best to describe these latter experiments first, and then 
to consider the nature of the substances formed by the action of bromacetic 
acid on triethyl-phosphine. 
Action of Chloracetic Acid on Triethyl-Phosphine. 
The apparatus employed in these experiments is shown in the figure. It 
consists of a distilling flask D, which can be immersed when necessary in the 
vessel E, containing cold water and shaken by the hand, the long indiarubber 
tube C permitting this, whilst a stream of hydrogen from the generator A is 
passing through the apparatus. 
A—Hydrogen generator. 
B—Sulphurie acid drying bottle. 
C—Long indiarubber tube. 
D—Small distilling flask. 
EK—Vessel full of cold water. 
F—Tap funnel, 
4-7 orms. of chloracetic acid (molecular weight=94°5) were placed in the 
distilling flask. The cork through which the tube C (connected with the 
hydrogen generator) and the tube of the tap funnel F pass was then fitted in, 
and hydrogen allowed to stream through the apparatus for some time. 
59 grms. of triethyl-phosphine were then placed in the tap funnel F, and 
allowed to drop slowly on to the chloracetic acid. 
The latter dissolved with considerable difficulty in the phosphine, and at first 
no action was apparent, but on shaking the mixture well, a dense syrupy liquid 
began to separate, and after some time most of the mixture had assumed this 
form, but a small quantity of a lighter liquid floated on its surface. The mixture 
grew very hot whilst this was occurring, and had to be cooled repeatedly by 
VOL. XXX. PART I. 3A 
