342 M. 11, Schneider on the Volumetric 



reduction, this equation is 



8o*-}2vo* + (6v 2 -2V)(7 2 + (V+^-^-X/uvJo- 



+ (vX- A 6 2 )(v/i-\ 2 )=0. 



It may he remarked that if <r=0, then a or b vanishes; and 

 therefore, from the original equations, vX— /a 2 =0, or v/j,— X 2 =Q, 

 which agrees with the result afforded by the foregoing equation 

 in a. Again, if <r=v, then c=0; and therefore, from the ori- 

 ginal equations, v 2 — X/x = 0. The left-hand side of the equation 

 in a; writing therein a=v, should therefore contain the factor 

 v 2 -Xyrx; its value in fact is v 4 -2X//,v 2 4-Xy, or (v 2 -X/a) 2 . 



If in the original equations we write a= -, b = ^, the equa- 



Z ST 



tious become 



x 2 + cyz — \z" 2 = 0, 



l/+CZX—fJLz' 2 = 0, 



(c 2 —v)z* + xy=:0, 



which are three homogeneous equations of the second order; 

 from which, if the variables x, y, z are eliminated, we have the 

 required equation in c. And it would not, I think, be difficult, 

 from the known formula for the general case, to deduce the fore- 

 going result corresponding to the very particular case which is 

 here in question. 



2 Stone Buildings, W.C., 

 September 25, I860. 



XLV. On the Volumetric Determination of Antimony. 

 By R. Schneider*. 



IN most analytical processes antimony is separated as sul- 

 phuret of antimony. As this body varies in composition, 

 and cannot therefore be directly determined, it is necessary to 

 convert it into some form in which it is easily estimated. As 

 far as ordinary quantitative analysis is concerned, this question 

 may be considered as settled; Bunsen's methodf of changing 

 sulphuret of antimony into antimoniate of oxide of antimony 

 leaves nothing to be desired for accuracy and certainty. Hitherto, 



* Translated from PoggendorfPs Annalen, vol. ex. p. 634. 



f Bunsen's method consists in precipitating the antimony in the usual 

 way by sulphuretted hydrogen, and oxidizing the sulphide of antimony by 

 means of strong nitric acid of spec. grav. 1*524, instead of ordinary nitric 

 acid. By another modification which he adopted, the sidphide was oxidized 

 by being heated with a large excess of oxide of mercury. For the details 

 of the process the reader is referred to the Chemical Gazette for 1858, 

 page 311, which contains a full translation of Bunsen's original memoir. 

 —Eds. 



