3IE. a. GOEE ON THE PEOPEETIES OE ELECTEO-DEPOSITED ANTIMONY. 799 
order given, ^0-06405, 0-06261, 0-06204, 0-06372, 0-06329, 0-06240, and 0-06377; 
mean 0-06312. The discharging point of perfectly similar bars was 205°-6 Fahr., and 
the highest temperature to which these were raised was 185°- 3 Fahr. ; nevertheleL on 
several occasions during their presence in the air-bath at the higher temperatures I 
observed that they evolved heat; and after the experiments, I found that they had 
entmely lost their heating property: their weights and specific gravities were, however, 
but veiy shghtly different from those found before the specific heat determinations, but 
their fi-actured surfaces were much less bright and of a lighter colour than those of 
unchanged antimony. From these experiments it appears that the discharge of heat by 
electro-deposited antimony is not necessarily attended by alteration of the specific heat 
of the substance ; because whilst the substance was gradually discharging the whole of 
Its peculiar heat, its specific heat did not sensibly diminish, as may be observed by 
examining the numbers obtained. 
67. An extra determination was made with two similar bars, weighing together upwards 
of 480 grains; raising their temperature onlyto 118°-0Fahr., the number obtained was 
0-0637; they still possessed the heating property, evidently because they had not been 
subjected to a sufiiciently high temperature to produce even a gradual discharge. The 
specific heat of the solution in ivhich the bars were formed was found by the method 
of cooling to be =0-6550, 
^ 68. Some determinations of the specific heat of antimony which had been suddenly 
discharged were also made. With two bars which had been changed in air at 60° Fahr., 
and weighing together about 730 grains, the following successive numbers were obtained 
— 0-0O33, 0-0545, 0-0549, 0-0547 ; mean =0-0543. And with thin pieces discharged in 
the hot-au- bath, and weighing nearly 740 grains, the numbers 0-0522 and 0-0533 were 
obtained. The results were checked by separate determinations of the specific heat 
of pui-ified antimony m the ordinary state of aggregation. The manifest reason why 
the specific heat of the suddenly changed bars was less than that of the gradually 
changed ones, was because they had by the sudden discharge been subjected to a very 
much higher temperature, and had therefore lost a larger proportion of their enclosed 
hquid, which is a substance of greater specific heat than metallic antimony. A similar 
reason explains why the thin pieces suddenly discharged in a heated atmosphere had 
less specific heat than the bars suddenly discharged in cool air. In all cases, the higher 
the temperature the substance had been subjected to in the process of discharge, 
—either by being suddenly instead of gradually discharged, or by being suddenly 
discharged in a non-conducting heated medium instead of in cool air (or in cold water 
or mercui-y, for example), or by discharging a large bulk instead of a small quantity, 
the greater was the loss of enclosed liquid, increase of specific gravity, and decrease of 
specific heat. 
e. Tem'perature at which the sudden discharge occurs. 
69. A number of experiments were made to ascertain the temperature at which the 
substance discharges its heat, in the following manner two perfectly similar specimens 
