610 Mr. J. Y. Buchanan on Chemical Work 



ice were allowed to melt at the temperature of the laboratory, which 

 ranged from 2° to 7° C. The melting thus took place very slowly, and 

 made it possible to examine the water fractionally. My experiments 

 consisted in determining the chlorine in the water by means of tenth- 

 normal nitrate of silver solution, and observing the temperature of the 

 ice when melting. 



A lump, which when melted was found to measure 625 cub. centims., 

 was allowed to melt gradually in a porcelain dish. When about 100 cub. 

 centims. had melted, 50 cub. centims. were taken for the determination 

 of the chlorine ; they required 13*6 cub. centims. silver solution, corre- 

 sponding to 0*0483 gramme chlorine. When 560 cub. centims. had 

 melted, 50 cub. centims. were titrated, and required 1*6 cub. centim. 

 silver solution, corresponding to 0-0057 gramme chlorine. The remainder 

 (65 cub. centims.) of the ice was then melted and 60 cub. centims. 

 titrated ; they required 0*39 cub. centim. silver solution, corresponding 

 to 0*0014 gramme chlorine. We have, then, in the first 50 cub. centims. 

 0*0483 gramme chorine, in the next 510 cub. centims. 0-0579 gramme 

 chlorine, and in the last 65 cub. centims. 0*0015 gramme. Hence the 

 whole lump (625 cub. centims.) contained 0*1077 gramme chlorine, or, 

 on an average, 0-1723 gramme chlorine per litre. A qualitative analysis 

 of the water showed lime, magnesia, and sulphuric acid to be present. 



Another piece of the ice was pounded and allowed to melt in a beaker. 

 When about half was melted, the water was poured off and found to mea- 

 sure 95 cub. centims.; 75 cub. centims. were titrated with silver solution, 

 and required 1*9 cub. centim. The remainder, when melted, measured 

 130 cub. centims., and required 0*9 cub. centim. silver solution. Hence 

 the first fraction of 95 cub. centims. contained 0*0085 gramme chlorine, 

 and the second of 130 cub. centims. 0*0032 gramme chlorine. The whole 

 quantity (225 cub. centims.) of ice, therefore, contained 0*0117 gramme 

 chlorine, or, on an average, 0*0520 gramme per litre. 



From these results it is evident that the ice under examination was 

 very far from being an homogeneous body ; and, indeed, nothing else 

 could be expected, when it is borne in mind that the ice in question owes 

 its existence, not only to the bond fide freezing of sea-water, but also to 

 the snow which falls on its surface and is congealed into a compact mass 

 by the salt-water spray freezing amongst it. 



The ice formed by freezing sea-water in a bucket was found to have 

 formed all round the bottom and sides of the bucket, and forming a 

 pellicle on the surface, from which, and from the sides and bottom, the 

 ice had formed in hexagonal planes, projecting edgewise into the water. 

 The water was poured off, the crystals collected, washed with distilled 

 water, pressed between filtering-paper, and one portion melted. It 

 measured 9 cub. centims., and required 4 cub. centims. silver solution, 

 corresponding to 0*0142 gramme chlorine, or 1*5780 gramme per litre. 

 The other portion was used for determining the melting-point. The 



