BENZYL PHOSPHINES AND THEIR DERIVATIVES. 567 



(4) A quantity of the crystals were removed, quickly dried from adhering oily matter 

 by pressure between filter-paper, then dissolved in bisulphide of carbon and mixed after 

 filtration with a solution of sulphur in bisulphide of carbon. An immediate precipitate 

 of fine needles occurred. These were filtered off, dried by pressure, then recrystallised 

 from boiling glacial acetic acid, in which they are only sparingly soluble. On cooling 

 nearly the whole of the compound separated in tufts of colourless fine needles. After a 

 single recrystallisation from acetic acid, the corrected melting point of the substance was 

 found to be 276° C. An organic analysis gave the following results : — 



Analysis. 



n \ n 9001 i °" 7935 CO. = 0-216409 C = 7408 per cent. 



(1) 2921 g av e{ . l704H2O==0 . 018933H= 6 . 4g n 



(2) 0-2654 ?ave J °' 7180 CO, = 0-195818 C = 73"78 per cent. 

 (2) 2654 S ave ( . 1558 H 2 O = 00l7311 H= 6-52 „ 



Obtained. 



Calculated for (C 7 H 7 ) 3 PS 





(1) 



(2) 





Carbon, . 



7408 



73-78 



75-00 



Hydrogen, 



6-48 



6-52 



6-25 



We have already mentioned that sulphide of tribenzyl phosphine is very difficult to 

 purify. Its melting point we had previously found to be 276. 



(5) Another quantity of the crystals, removed from the upper portions of the crystalline 



cake, and which looked pure and free from the oily matter, was very carefully removed 



and rapidly thrown into a filter placed in a funnel in a deep beaker full of carbonic 



anhydride. They were then several times washed with alcohol and the filter containing 



them rapidly transferred to a wide glass tube full of carbonic anhydride, which was 



then plugged with a perforated cork, and a stream of dry carbonic anhydride passed 



through it, while the tube was gently warmed. By these means the crystals were washed 



and dried with a minimum chance of oxidation. The dry crystals were then rapidly 



transferred to a small tube full of carbonic anhydride, and a combined organic analysis 



and phosphorus determination made by the method already alluded to. 



Analysis. 



C 1-0823 CO =0-295172 C = 81-22 per cent. 



0-3634 gave -< 02455 H 2 = 0027277H = 75 

 I 01352 Mg 2 P 2 7 = 0037758 P = 1039 



Obtained. Calculated for (C 7 H 7 ) 3 P 

 Carbon, . . . 8122 82'89 



Hydrogen, . . . 7 -50* 690 



Phosphorus, . . . 1039 10-19 



The numbers obtained in the above analysis are sufficiently close to those calculated 

 for tribenzyl phosphine, to prove that we had at last succeeded in isolating that sub- 

 stance, if not in an absolutely pure condition. 



In another experiment we still further identified the tertiary phosphine by obtaining 



* The bydrogen is no doubt too high, as the combustion tube was not warmed, and cold oxide of copper was used — 

 both no doubt containing hygroscopic moisture. 



VOL. XXXV. PART II. (NO. 15). 4 Z 



