ME. G. GOEE OJJ- THE PEOPEETIES OE ELECTEO-DEPOSITED ANTIMOXY. 803 
houi-s : the bar was then taken out ; it had lost the whole of its heating power, and 
weighed 275-6 grains = a loss of 0-26 per cent, in weight. 
And 2nd. If two pieces of active antimony are suddenly discharged, and from any cause 
the temperatures they acquire are different, the amounts of vapour they evolve are also 
different; thus a quantity of thin fragments was divided into equal parts of 180 grains 
each ; the fii-st was placed in a fine brass wire-gauze basket with a wire-gauze lid, and 
raised quickly to a temperature of 163°-0 Fahii. in the air-bath, and then at once discharged 
in the open air at 60 °Fahe., by momentary contact of a heated wire; and the second 
portion, placed in the same basket, was surrounded by ice and cooled to 34 °Fahe., and 
-similarly discharged in the air at 60° Fahr. ; the former evolved its heat instantaneously, 
and lost 8-85 grains, or 4*916 per cent, in weight; and the latter discharged feebly and 
much less rapidly, and lost 5-40 grains, or 3-00 per cent. It appears from these various 
expeiiments that the evolution of vapour is not a cause nor even a necessary consequence 
of the change, but only occurs when the temperature of the substance during the dis- 
charge is consideiably raised; and it makes no difference whether the requisite tempe- 
rature is acquired by means of internal heat or by heat from external sources. 
76. In all instances, and these were very numerous, the heat from the discharge alone 
was insufficient to expel more than three-fourths of the contained liquid, and in those 
instances, whether of sudden or gradual discharge, the remainder, making a total in 
each case of upwards of sia: percent., was always readily expelled by fusing the metal in 
a test-tube. 
f. Influence of temperature upon the amount of heat evolved. 
77. Two similar bars were taken, No. 1 weighing 257-21 grains, and No. 2 weighing 
24o-90 grains: the first was placed in the wire-gauze basket and cooled to 34°-0 Fahr., 
then at once transferred to the calorimeter (which was at 57°-6 Fahr.), and instantly 
discharged; the second was also placed in a similar basket and heated to 157 °- 15 Fahr. 
in the air-bath; the basket and bar were then instantly lowered into the calorimeter 
(which was at 57°* 75 Fahr.), and at once discharged; the calorimeter of the former 
attained a maximum temperature of 6 7°- 35 Fahr. in nine minutes, and of the latter a 
maximum of 69 4 Fahr. in the same period. The following are the various specific heat- 
^alues in water of the substances, &c. ; — 
No. 1. 
Antimony 257 21 grains (sp. heat =0'06312) = 16-235 grains of water 1 Raised from 34°-0 to 67°-35 
Brass basket (sp. heat =0-0939 ) = 6-242 grains of water J Eahe. = 33-35 degrees. 
22-477 grains of water 
Immersed part of glass tube of calorimeter (sp. heat=0-1770)= 28*718 grs 
Mercury of thermometer (sp. heat=0-033 )= 2*070 grs 
Portion of stem of thermometer (sp. heat=0-1770)= 3-600 grs 
Water of calorimeter 743-764 grs 
778-152 grs 
. 01 Wtibor 
. of water 
. of water 
. of water 
Eaised from 57°-6 
to 67°-35 Eahb. 
= 9*75 degrees. 
5 A 2 
