802 ME, G. GOEE OX THE PEOPBETIES OE ELECTEO-DEPOSlTED AMIMOXT. 
minute fragments. The loss of weight hy evolved vapour- was 5-99 ^ains =1-68 per 
It lu several cases, when the substance has been rapidly deposrted and drscharged 
vrithin a short period, the action has been instantaneous, and the metal has been 
shattered into minute particles (see 25.). 
e. The evolution of vapour not a cause hut an effect of the heat 
75 The evolution of vapour and consequent loss of weight by the dischai^e appears 
to be entirely dependent upon the temperature which the substance acqun-es durmg he 
discharge Lt. If the substairce acquires a very high temperatui-e, such as when it is 
dll^hm-ged in a hot-air bath, its loss of weight is considerable ; but if it does not acqrrr^ 
a very high temperature, as when it is gradually discharged by suspentog '‘>”^ 01 - 
air bith at about 150° or 170° Fahe„ or in a hot-water bath at 212 F-vhe., its loss 
weight is very small. The following experiments will illustrate this statement . 
Three perfectly similar bars, taken the precious day from the depositing hqmd. were 
separately discharged in the hot-air bath : the first w-as gradually raised in tempeiatiue 
during one hour and forty minutes from 60° to 196°Fahe., it then suddenly discharged 
with considerable force; the second was maintained at a temperature i aiding rom 
170° to 178°Fahe. during two hours and eleven mhiutes, it then suddenly disch 
its heat with less force; and the third was kept at a temperature varjmg fi-om 1.0 to 
177°Fahe. during nine hours and twelve minutes, and (after the eat appearec o . 
discharged) during the last two hours at 180° Fahe., and finally at 186° Fahe ; it ecu vec 
its heat gradually without any sudden discharge, and was found to have entire jlo s 
thermic power. The following are the weights of the bars, their specific giavn i s. 
losses of vapour, &c. - 
No. 1. 
No. 2. 
No. 3. 
grams. 
249-78. 
254-65. 
299-65. 
Before the experiment. 
Specific gravity 5-811 at 66° Fahr. 
Specific gravity 5-825 at 63 -3 Fahr. 
After the experiment. 
graius. grains. 
No. 1. 238-02 lost ll-76=:4-7 per cent. 
No. 2. 248-68 lost 6-95=:2-34 percent. 
No. 3. 297-41 lost 2-24=0-747 per cent. Specific gravity 5-8o3 at 62 -6 Iahr. 
Also two perfectly similar bars, the first weighing 251-92 grains, and the second 
weighing 256-18 grains, were deprived of their energy ; the first suddenly in the au-bath 
of the calorimeter at 60° Fahe., and the second gradually by suspending it in boding 
water during six hours. The first one lost 10-8 grains =4-28 per cent., and the secoiu 
lost 0-73 grain =0-28 per cent. ; and another bar, weighing 256-18 grams, was immersei 
in cold water, the water heated to boiling m thirty minutes, and kept boiling during six 
