1887.] Prof. Letts and W. Wheeler on Benzyl Phosphines. 71 
phosphine in dry hydriodic acid gas, — by saturating a solution of 
the phosphine in benzol with dry hydriodic acid, or by dissolving 
the phosphine in warm fuming hydriodic acid. 
By the first method it is obtained in snow-white scaly crystals, 
like benzoic acid ; by the second, as a seemingly amorphous, bulky 
precipitate ; whilst by the third, it is also obtained in the crystalline 
state. 
A specimen prepared by the first method was analysed — 
•6090 gave *5630 Agl = -30431 = 49-97 %. 
calculated per C^H^PH2.H1 - 1 = 50-39 %. 
The hydriodate, when pure and dry, is permanent in dry air ; but 
a trace of impurity causes it to become brown. It is rapidly decom- 
posed by water, and instantly by caustic potash solution, the phos- 
phine being set free. 
It is very insoluble in benzol, slightly soluble in ether, and spar- 
ingly soluble in warm fuming hydriodic acid. 
Hyclrohromate. — Hofmann could not obtain this compound, but 
we found that it could be prepared with the greatest ease, either by 
saturating a solution of the phosphine in benzol with gaseous hydro- 
bromic acid, or by dissolving the phosphine in the fuming (aqueous) 
acid. By the latter method it is obtained in scaly crystals, very 
similar to the hydriodate. 
Its analysis gave a small deficiency of bromine — probably due to 
slight deliquescence, or to a trace of impurity — 
Calculated for 
Obtained. BzPH2.HBr. 
Bromine, . 37-9 39-0. 
The salt is insoluble in benzol, and only very slightly soluble in 
warm fuming hydrobromic acid. 
It decomposes rapidly in contact with water, and instantly with 
caustic potash. 
Hydroclilorate. — Hofmann did not succeed in obtaining this salt, 
but it may be produced by similar methods to those which we em- 
ployed for obtaining the two last-named compounds. 
On passing gaseous hydrochloric acid into the pure phosphine 
dissolved in benzol, no effect is produced until the solution is quite 
saturated. Then white crystalline scales begin to form. 
