304 PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 
produced ; but if concentrated and hot solutions of the two are mixed, the 
chloroplatinate separates on cooling in groups of thick needles of a light orange 
colour. The compound is a very beautiful one, and frequently the crystals 
attain the length of half an inch. 
(1) 05763 lost 00143 = 2:3 per cent. HO 
05763 gave 01461 Pt =25°3 i. Pt 
05763 , 0629 AgCl = 270 x Cl 
(2) 10086 ,, 0-257 Pé =25°4 fy Set 
10086 , 02733501 =271 , CI 
Calculated for 
Obtained. es ——— 
Cree AD (CH)? <6 coon , PtCl,, H,0 
Water; . : : Oe ses ; ; pages) 
Platinum, ; : 25:3. 25°4 ; ; 25°2 
Chlorine, . : : 270 27-1 5 . 27:2 
Hydrobromate of Triethyl-Phosphorus-Betaine.—9 grms. of the pure hydro- 
chlorate were dissolved in water and converted into hydrate by the action of 
oxide of silver. From the filtered solution the small quantity of silver dis- 
solved was precipitated by hydrobromie acid, and to the solution filtered from 
bromide of silver an excess of hydrobromic acid of constant boiling point was 
added. The mixture was then evaporated in the water bath until a syrup 
remained. This was maintained at a gentle heat to drive off excess of hydro- 
bromic acid. When this had been accomplished the syrup (which was slightly 
brown in colour) was left to itself for a short time, and solidified to a radiating 
crystalline mass. It was dissolved in hot alcohol, and ether was then added 
cautiously to the solution until an oily liquid began to precipitate. The 
mixture was now allowed to stand, and soon began to crystallise. 
The crystals which formed consisted of colourless and very thin quadratic 
plates, which were in many cases half an inch across. 
Some of the crystals were dried im vacuo over sulphuric acid, and a 
determination of bromine made by VoLHARDT’s volumetric process. 
0:0880 required 34 cc. centinormal AgNO,=0:0272 Br=30°9 per cent. Br 
Br 
Calculated for (CoH).PC 
Obtained. CH,—COOH. 
Bromine, 30°9 : , , ; : ele: 
The hydrobromate is somewhat deliquescent, but resembles in other 
properties the hydrochlorate. 
In order to be quite certain that it was really a betaine derivative, some of 
it was reconverted into hydrochlorate by the action of oxide of silver and then 
of hydrochloric acid. . This solution yielded the characteristic chloroplatinate 
when it was mixed with chloride of platinum. The necessity for proving that 
. 
| 
. 
; 
; 
