1887.] 
Mr J. Y. Buchanan on Ice and Brines. 
145 
In Table IX. are given the volumes occupied by the ice (with 
inclosed brine) formed by freezing 100,000 c.c. (at 0° C.) of a 
water containing chloride of sodium equivalent to 7 grammes 
chlorine in 1,000,000 cubic centimetres (at 0° C.). 
Table IX. — Water containing 7 parts Cl in 1,000,000. 
Temp. 
0 C. 
Water 
frozen. 
c.c. 
Ice 
formed. 
c.c. 
Brine 
remain- 
ing. 
c.c. 
Ice and 
Brine, 
c.c. 
Pettersson 
III. 
Vol. of Ice 
at T°. 
c.c. 
Diff. 
T 
Vj 
®i 
v 2 
Vn 
P 
P-v 2 
-0*07 
99000 
107979 
1000 
108979 
108980 
1 
-0*10 
99300 
108306 
700 
109006 
109007 
1 
-0*15 
99533 
108561 
467 
] 09028 
109038 
10 
-0*20 
99650 
108687 
350 
109037 
109048 
11 
-0*40 
99825 
108879 
175 
109054 
109057 
3 
The volume (v 2 ) of the ice and brine formed on freezing this 
water is compared with that (P) observed by Pettersson in freezing 
a sample of the distilled water in ordinary use in the laboratory. 
It will be seen that the volumes observed by Pettersson agree 
very closely with those calculated for a water containing 7 parts of 
chlorine in a million, on the assumption that the saline matter is 
contained entirely in adhering liquid brine. 
The irregularities in the melting-points of bodies like acetic acid ? 
to which Pettersson refers, are without doubt due to a perfectly 
similar cause. 
Also the very low latent heat observed by Pettersson for sea- 
water is to be explained by the fact that the salt retains a con- 
siderable proportion of the water in the liquid state even at tem- 
peratures many degrees below the freezing-point of distilled water. 
Thus, he made two determinations of the latent heat of sea-water 
containing P927 per cent. Cl and 3*53 per cent. salt. The freezing 
took place in the one case between the temperatures - 9°*0 and 
— 7°*47 C., and in the other between -8°*35 and -6°*94 C., and 
the results he found were 52*7 and 51*5. The mean initial tem- 
perature in these two experiments is -8° *7 C., and the mean final 
temperature - 7°*2 C. At - 7° *2 C. ice would form on cooling, and 
would melt on warming a solution of chloride of sodium containing 
6*48 per cent. Cl, which represents 11*87 per cent, of the sea salt. 
In order to concentrate a brine containing 3*53 per cent, salt to one 
VOL. XIV. 23/9/87 
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