806 ME. G. GOEE OX THE PEOPEETIES OF ELECTEO-DEPOSITED AXTDIOXY. 
antimony contained in it determined as sulphide b} sulphuretted hydiogen. and after 
separating the excess of sulphuretted hydrogen from the filtrate b\ adding solution of 
sulphate of sesquioxide of iron and filtering, the total amount of chlorine m as determined 
as chloride of silver ; the amount of chlorine due to the terchloiide found was then 
subtracted, and the remainder estimated as hydrochloric acid. 
h. Is the ])eculiaT change of antimony necessarily attended hy a chemical change? 
83. To ascertain whether during the act of gradual discharge the acid terchlonde of 
antimony contained in the substance passed from a state of stronger combination with 
the metal to a state of weaker combination, I took 200 grains of unchanged antimony 
powder, placed it in equal portions in two small fiasks, added to each 500 grams of 
distilled water ; immersed one of the flasks in boiling water during thhty mmutes, to 
discharge the heating power of its metal, and then replaced the evaporated water; 
added 50 grains of tartaric acid and 106 '35 grains of hydrochloric acid to the contents 
of each flask, and allowed both vessels to remain at 60° Fahe. during two days. The 
two liquids were then separately filtered, the contents of the filters washed with equal 
quantities of a solution of tartaric acid, the washed residues dried, the filtrates pre- 
cipitated by sulphuretted hydrogen, and the precipitates washed and dried. The con- 
tents of the heated flask yielded 93T5 grains of metallic residue possessing no heating 
power, and 4’20 grains of precipitated tersulphide of antimony : the contents ot the 
other flask gave 97-24 grains of residue possessing the heating power, and I'TT grain 
of tersulphide. I have also found on other occasions, when the powdered active srrh- 
stance had lost its peculiar property with extreme slowness (see 86.), and its weight 
and chemical composition had remained unaltered, that the terchloride of antimony 
corrtained in it was much more completely and easily extracted hy means of solvents 
than whilst the powder retained its heating power. No appearance of mechanical 
mixture of terchloride of antimony with metallic antimony could be detected in changed 
powder by means of a powerful microscope. 
84. From these observations it appears, that during the act even of gradual dis- 
charge, the terchloride of antimony changes from a state of more intimate to a state of 
less intimate union with the metal ; but whether that change consists of diminished 
chemical, or simply diminished mechanical union, I have been unable to ascertain. 
i. Can the terchloride of antimony he separated without destroying the heating property? 
85. Several portions of the unchanged powder were digested in strong hydrochloric 
acid, solution of tartaric acid, and in strongly alkaline liquids for lengthened periods of 
time, at the atmospheric temperature, with an expectation of extracting at least the 
greater portion of the terchloride and retaining the whole of the heating power ; but it 
was found that in every instance the heating property gradually diminished, and in 
about six or seven months entirely disappeared. The loss of heating power was not 
alone due (if at all, see 86.) to the abstraction of the terchloride by the solvents, because 
