3IE. G-. GOEE ON THE PEOPEETIES OP ELECTEO-DEPOSITEH ANTIMONY. 8(J7 
It occurred in those samples from which only about one-half of the terchloride had been 
dissohed, as well as in those from which the whole had been extracted (see also 52.). 
j. Does electro-dejjosited antimony gTadiially change? 
86. Othei portions of each of the samples of powder used in these experiments (85.) 
were enclosed in weU-stoppered bottles, and kept during the same period (seven months) 
in a cool place not exposed to sunshine; in each instance the heating power entirely dis- 
appeared, and the powder became somewhat oxidized and acquired a slightly acid odour 
fiom paitial separation of the terchloride; several other samples of equal age behaved 
similaily. Di. Peecy has also obtained similar results by placing the active powder in 
a capsule o'sei strong sulphuric acid for several months. Some active powder, exposed 
to strong daylight during two months, still retained a heating power. Coarse granules 
of the active substance lost a large portion of their power in seven months : and solid 
bais, nearly a quarter of an inch thick, which had been formed several months before, 
and had been more exposed to the atmosphere, rvere also found to be slightly but 
distinctly weakened. 
87. Fiom these and other observations, it is certain that electro-deposited antimony 
undergoes a gTadual change or decomposition even at 60° FiiHE., attended by a dimi- 
nished union between the terchloride of antimony and metal, and gradual and complete 
loss of its peculiar heating power, similar to its change in heated air at 160 ° Fahb., or 
in boiling uater (83.), but much more slowly. It also appears that the substance in a 
finely ^ divided state loses its heating power with much greater rapidity than when in a 
massive f 07111 ; in the former case it requires only a few months, while in the latter case 
it lequires at least several years (26.); but whether this difference is due to the difference 
oi cohesion or to the difference of amount of exposed surface of the substance, I have 
not ascertained. 
k. Miscellaneous ohsei'vations. 
88. A small quantity of mercury in a gutta-percha capsule, was made the cathode 
in the tartaric acid solution (2.), and a deposit of grey antimony formed upon it; a pecu- 
liar appearance and disappearance of metallic films upon the surface of the mercury 
occuried on discontinuing and renewing the electric current, apparently caused by 
depo.sition of films of antimony and absorption of the films by the mercury ; this was 
lepeated many times until accumulation of antimony in the mercury interfered. By 
passing a continuous feeble electric current into the mercury, a compound of that 
metal and antimony, of a pasty consistence, was formed, which gradually spread (in an 
arborescent form interspersed by warty excrescences) by capillary action all over the 
inner and outer surfaces of the small capsule, and transferred the remaining fluid mer- 
cury over the edge of the capsule into the depositing vessel. If ordinary chloride of anti- 
mony was substituted for the tartaric acid liquid, the whole of the deposited black briglit 
antimony remained unabsorbed upon the surface of the mercury, and exhibited tlie 
cohesive action (17.) strongly, as long as the deposit was sufficiently thin, 
