1887.] 
Mr J. Y. Buchanan on Ice and Brines. 
135 
jDercentage of chlorine. The weight of the brine remaining after 
any freezing operation is found by multiplying the weight of the 
original water used by the ratio of the chlorine percentage found 
in the original water to that found in the brine. The difference 
between the weight so found and that of the original water is the 
weight of the ice formed. In Table II. the results of this calcu- 
lation are given for Experiment III. on pure sea-water from the 
Clyde, and for Experiment IY. on the same water diluted with an 
equal weight of distilled water. 
Table II .' — Calculation of Ice formed , on the basis of the Salinity 
of the Original Water and of the Residual Brine. 
No. of Experiment, . 
III. 
IY. 
Weight of original water (grammes), . 
W 
300 
300 
Per cent. Cl in ditto, ..... 
c 
1-836 
0-923 
Per cent. Cl in mother-liquor, 
K 
2-212 
1-153 
£ 
Weight of mother-liquor, . . W-^- = 
L 
249*0 
293-3 
Weight of ice, .... W-L = 
I 
51-0 
60-7 
Sea-water, like other saline solutions, is easily cooled several de- 
grees below its freezing-point before crystals begin to form. While 
cooling down to and below what was known to be its freezing-point, 
simultaneous observations of the temperature of the sea-water and 
the freezing-bath were made from half minute to half minute. From 
these observations, the rate of abstraction of heat for different differ- 
ences of temperature of sea-water and bath was found. At a given 
moment a minute splinter of ice (weighing much less than a drop of 
water) was introduced. Crystals immediately began to form, and 
the temperature rose in from ten to fifteen seconds to the freezing- 
point. During the freezing the temperatures of bath and sea- water 
were observed at regular intervals. The heat removed is thus made 
up of that eliminated during the few seconds when freezing began 
and the temperature rose to the freezing-point, which is found by 
multiplying the rise of temperature by the weight of liquid, and 
that removed during the subsequent cooling, which is found 
from the duration of the operation and the rate of loss of heat, 
deduced from observations made during the cooling. The specific 
heat of the solution is taken as that of the water which it contains, 
