PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 325 
p. 304) and it was found (1) that it readily yielded a sparingly soluble platinum 
salt ; and (2) that it yielded carbonic acid on heating (see p. 316). 
Now it has been already mentioned that no sparingly soluble platinum salt 
could be obtained from the product of action of bromacetic acid or triethyl- 
phosphine, and it had also been found that this product yields only a very 
small quantity of carbonic acid on heating (see p. 328), both of which results 
are against the supposition that any of the true hydrobromate is formed. 
Fresh experiments were, however, necessary to decide this point. 3:5 
erms. of carefully dried and purified bromacetic acid were dissolved in about 
20 cc. of perfectly pure and dry ether. 3 grms. of triethyl-phosphine were 
dissolved in about the same quantity of ether, and the two solutions were 
simply mixed, without any special precautions. ‘The flask in which the mixture 
was made was then corked and placed in cold water: oily drops precipitated. 
The flask was vigorously shaken from time to time, and was then left to 
itself in the cold water. The contents began to crystallise in a short time, 
and soon solidified to a solid mass. After a few hours this was broken up 
and thoroughly extracted with dry ether. It was then placed in vacuo for 
some hours. 
Some of the snow-white product thus obtained was titrated with standard 
nitrate of silver solution, and was found to contain the amount of bromine 
required for the formula C,;H,,0,PBr. 
(1) 03316 required 13:2 cc. AgNO,=0:1056 Br=31'8 per cent. Br. 
(2) 04707 * eso 3 Se O1480) ed |e. Br. 
Obtained. 
r 1. Calculated for C,H,,0,PBr. 
Bromine, . 318 . di4. ; : ole: 
A portion of the product was treated with oxide of silver, and hydrochloric 
acid was added to the filtered solution. On the addition of chloride of 
platinum to this, a sparingly soluble orange-coloured salt separated exactly 
like the chloroplatinate of triethyl-phosphorus betaine. 
Moreover, on heating some of the product, carbonic acid was given off in 
abundance, no charring occurred, and the residue solidified. On treating the 
latter with oxide of silver, hydrochloric acid, and chloride of platinum in 
succession, the characteristic chloroplatinate of triethyl-methyl-phosphonium 
separated. 
These results then are quite different from those previously obtained, and 
indicate that some at least of the body produced by the action of bromacetic 
acid on triethyl-phosphine is the true hydrobromate of triethyl-phosphorus 
betaine. There was, however, no doubt whatever in the author’s mind, from 
VOL. XXX. PART I. 3D 
