06 MR. WILLIAM CARLETON WILLIAMS 



The simplest formula agreeing with these numbers is 

 Sb ? 4 G 7 , or three molecules of antimony pentachloride 

 in which four atoms of oxygen replace eight of chlorine. 



Calculated. Found. 



Antimony 53'94 53*89 



Chlorine 36*62 36*58 



Oxygen 9*44 



IOO'OO 



From the above results it is clear that the simple reaction 

 by which phosphorus oxychloride may be formed is not re- 

 produced under similar circumstances in the antimony 

 series, but that this element, in agreement with its general 

 deportment, gives rise to more complicated compounds. 



The oxychlorides derived from antimony trichloride have 

 been frequently examined ; the results of the analysis of 

 powder of algaroth made by different investigators vary 

 considerably ; and Sabanejeff has recently shown that these 

 differences are probably due to the presence in the sub- 

 stance of antimony trichloride in varying quantities. This 

 impurity he gets rid of by washing the oxychloride, ob- 

 tained by the action of a large excess of water on the 

 trichloride, with ether or carbon disulphide, in which the 

 trichloride dissolves. In this way he obtains a compound 

 having the constant composition Sb 4 Cl 2 5 , or two mole- 

 cules of trioxide, in which one atom of oxygen is replaced 

 by two of chlorine; whilst a simpler monoxychloride, 

 Sb O CI, is prepared by acting with only from 2 to 10 

 molecules of water on the trichloride ; but this, on 

 treatment with ether or carbon disulphide, loses tri- 

 chloride and yields Sb 4 Cl z 5 , thus : — 



5 Sb O Cl=Sb Cl 3 +Sb 4 Cl 2 5 . 



The results of my experiments lead me to the conclusion 

 that the body obtained by the action of boiling water on 



