010 PROF. LETTS AND MR R. F. BLAKE ON 



solves easily in alcohol, and it is also soluble in ether. It is a monobasic acid, and most 

 of its salts are very soluble. They are consequently troublesome to obtain pure, but 

 the following were prepared and analysed. 



Barium Benzyl Phosphinite. — Obtained by neutralising the crude acid formed by 

 the oxidation of the primary phosphine, filtering off the barium phosphate, boiling to 

 precipitate the barium phosphinate, again filtering and concentrating to a syrup. The 

 latter placed in vacuo solidified to a granular crystalline mass. This was squeezed as 

 dry as possible in a cloth filter, and for analysis a sample was pounded up and exposed 

 to the air until it ceased to lose weight. 



"■e* 



Analysis. 



1-1383 lost at 110° C. 01443 H 2 = 12-67 per cent. 

 1-1383 gave 0-5119 BaSO 4 = 0-301 Ba = 26-44 „ 



Obtained. Calculated for (C 7 H 7 HP0 2 ) 2 Ba,4H 2 



Water, . . . 1267 1387 



Barium, . . . 26-44 2639 



The salt in all probability suffers a slight decomposition at 110° C, and also becomes 

 partially oxidised. For after it had been heated and was dissolved in water, a distinct 

 odour of the primary phosphine was observed. No doubt these facts account for the 

 discrepancy between the observed loss at 110° C, and the calculated amount of water of 

 crystallisation. 



Calcium benzyl phosphinite was obtained by neutralising a solution of the acid 

 with chalk and evaporating the filtered solution. The salt separated out in crystalline 

 crusts during the evaporation in a very characteristic manner. It appears to be less 

 soluble in hot than in cold water. 



Analysis. 



•6943 lost at 110° C. 01 13 = 1-62 per cent. 

 •6943 gave 0-1070 CaO = 0-76428 Ca = lL00 „ 



Obtained. Calculated for 3{(C 7 H 7 HP0 2 ) 2 Ca},H 2 



Water, .... 1-62 1-68 



Calcium, ... 1100 11-23 



Magnesium Benzyl Phosphinite. — This salt was prepared by boiling a solution of 

 the acid with excess of carbonate of magnesium, filtering and concentrating the solution 

 first in a water-bath, and afterwards in vacuo over sulphuric acid. When the solution 

 grew syrupy, crystalline crusts were slowly deposited. 



Analysis. 



07354 lost (after 8 days' heating) at 110° C. 01538 H 2 = 20-91 per cent. 

 0-7354 gave 01938 Mg 2 P 2 7 = 0041 9 Mg = 5'69 





Obtained. 



Calculated for (C 7 H 7 HP0 2 ) 2 Mg,5H 2 



Magnesium, 



569 



5-66 



Water, 



2091 



2122 



