5 
determining the percentage of antimony and chlorine in pure 
antimony trichloride, the results agreeing closely with each 
other and with the theoretical composition. The objection 
to Schaeffer’s method of decomposing the oxychloride by 
boiling with a solution of sodium carbonate is that the pre- 
cipitated oxide of antimony being in a very finely divided 
state a portion of it is very apt to pass through the filter on 
washing. 
The simplest formula which agrees with the analytical 
results is Sb 3 Cli 3 0 or three molecules of pentachloride in 
which two of chlorine are replaced by one of oxygen. 
Calculated. 
Found. 
Sb 3 
43-89 
.. 43-46 
C1 13 .... 
54-71 
. 54-75 
0 
1-90 
— 
100-00 
That this is a definite compound and not a mere mixture 
of pentoxide and pentachloride (Sb a 0 5 + 14SbCl 5 )is evident 
from the fact that the latter substance is not dissolved out 
by washing with carbon disulphide. The calculated per- 
centage of pentoxide contained in this compound is 7"68 ; 
on heating 2-517 grams of the oxychloride in a tube retort 
a residue of 0-1799 grams of pentoxide remained, corres- 
ponding to a percentage of 7 "14. 
The second oxychloride formed by heating the mixture of 
one molecule of pentoxide and three of pentachloride is 
produced only in small quantities as yellowish crystals. To 
obtain it in the pure state, that portion of the tube in which 
the substance is found is cut off and after the tube has been 
re-sealed it is placed in a slanting direction in a vessel con- 
taining water heated from 85° to 90 c . The Sb 3 Cl I3 0 melts 
and runs down, leaving the other less fusible oxychloride 
behind ; this is then dried on a porous plate in vacuo over 
solid caustic potash. Two determinations showed that the 
melting point of this substance is 97°‘5 C. 
