518 



Dr. E. J. Mills on Elective Attraction, 



tlie supposition that tlie rest of the lithium was combined with 

 chlorine; the weights of phosphoric oxide and oxychloride admit 

 of calculation, and the value of a can be assigned. In I. some 

 of the residue was lost, and the analytical statement, although 

 available for calculating the ratio (r) just alluded to, does not 

 represent each total weight. 



II. 



1-2659 

 2-7842 



128^ 



1-2648 



2-Qnb 



130 = 



I. 



Mtrate taken 2'3604 



Residue 4-57U0 



Temperature 121° 



Composition of the residue, viz. : — 



Lithic chloride I — 



Lithic nitrate ' — 



Phosphoric oxychloride 



Phosphoric oxide I 



Argentic chloride i2-77Qo'] j4-3458 3-8380 



Magnesic pyrophosphate. [1-4077] | 2-2356 2-1720 



'/' 1-97 



III. i IV. 



VI. 



VII. 



0-7065 



0-5514 0-3315 6315 



1-8318 1-7411 0-9710 ■2-2Z2G 



134= 140^ 133=-5, 119° 



1 



[ 



0-3396 — 1 0-3431 



— 



none — 0-0723 



... 



•7178 ... 1-0327 



... ; -6919 ... -7214 



3-0084 3-1599 1-7295 4-0548 



1-7832 



1-6008 -8964 1-8752 



I 1-94 ! 1-77 : 1-69 



1-97 

 1-64 



1-93 ,216 

 — 1-59 



Mean value of /- (V. and YII.) .... 2*06 



3i a „ .... 1-61 



r (L, IL, III., IV., andVI.) I'86 



In the last group of experiments r closely approaches its value 

 in the first group, where a is known. The value of a may there- 

 fore be taken generally as 1*61. The mean of all the determi- 

 nations of 7' is 1-92; and it can easily be shown by means of 

 the data furnished in experiment Y., that the residue, so far as 

 it had taken part in the reaction, had a composition nearly to be 

 represented by the following formula : 



3LiCl,2POCF,2P2 0^ 



which gives /' = ! "94 and « = 1-50. 



Subsidiary Operations. 



In order to obtain some information as to the nature of the 

 gaseous products of the action of phosphoric oxychloride on ni- 

 trates, it was manifestly necessary to select a mtrate upon which 

 that reagent has considerable action. The theoretical excess of 

 oxychloride, indicated by the equation 



3Pb(X03)2 + 2POCF=Pb3(PO*)2 + 6N02CI, 



could not be employed, inasmuch as that quantity is insufficient 

 to cover the solid salt, and another well-known reaction was 

 therefore to be apprehended from the altered chemical conditions 

 due to purely mechanical circumstances. The fact that about 



