Le ill 
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| Barium, Strontium, and Caleium: 999 
By these means the reaction was rendered more equable than it 
could become in operating. with one series more highly hago 
a. under such circumstances, the reaction» may, at the 
outset, be sufficiently powerful to produce ignition, as Ihave of- 
_ten observed; after fifteen or twenty minutes it may become too 
feeble in electrolyzing power to render the continuance of the 
process in the slightest degree serviceable. Agreeably to my ex- 
perience, as the ratio of the calcium to the ‘mercury increases, the 
amalgam formed becomes so much more electro-positive as to 
balance the electro-negative influence of the voltaic current.  Af- 
ter reacting with one series of two hundred pairs, of one hun- 
dred square inches each, for seventy minutes, I have found the 
proportion of calcium to be only one six-hundredth of the amal- 
gamated mass obtained. r 
In this lies the great difficulty of obtaining any available quan- 
tity of the radicals of the alkaline earths by electrolyzation ; espe- 
cially in the case of calcium. It is easy, by a series of only fifty 
pairs, to produce an-amalgam with that metal, which, when ex- 
posed to the air, will become covered with a pulverulent mixture 
of lime and mercury; but, in such case, the quantity of calcium 
taken up by the mercury, when estimated by the resulting oxide, 
will be found almost too small to be appreciated by weighing. 
_ To incréase the quantity of calcium to an available extent I have 
found extremely difficult, since, as the process proceeds, the chem- 
ical affinity becomes more active, while the electrolyzing power 
becomes thore feeble. © = 
That a change should be effected in mercury, giving to it the 
characteristics of an amalgam, by the addition of a six hundreth 
part of its weight, cannot be deemed difficult to believe, when it 
is recollected that Davy found that when, by amalgamation with 
ammonium, a globule of mercury had expanded to five times its 
Previous bulk, it had gained, in weight, only one twelve thou- 
sandth part.* * 
As the affinity between the chlorine and the radicals of the 
alkaline earths increases in strength with the temperature, and as 
heat is eVolved in proportion to the energy of the voltaic action, 
the disposition of the elements separated by electrolyzation to re- 
Unite is, in this way, promoted. Hence the necessity of refrige- 
ration, 
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* Sixty grains of mercury contained only one two hundredths of a grain. See 
Nicholson’s Journal, Vol. xxxim, p. 213. 
