3o Chemical and Physical Notes 



by weight of chlorine in the same water. From these few 

 remarks, it will be seen that the mutual interaction between 

 ice, salt, and water must be taken into account in interpreting 

 the results of the sea-temperatures of the Antarctic. 



Sea-Ice as met with in Polar Seas. The above law refers 

 to ocean waters which contain not more than 4 per cent, of 

 dissolved matter. In the course of a Polar winter the sea 

 freezes to a thickness of 8 or 10 feet, and in proportion as the 

 ice gets thicker, the actions and reactions between ice and 

 brine and salt and water become more complex, and the law 

 of freezing is no longer so simple as that stated above. 



Sea-ice, as it occurs in the Arctic ocean, has been 

 described in great detail by Weyprecht, in a work 1 which 

 should be included in the library of every Antarctic expedi- 

 tion. The " Tegetthoff," which was Weyprecht's ship, was 

 beset in the pack in lat. 76 18' N., long. 61 17' E., on 

 August 13, 1872. Twenty-one months later she was still 

 a prisoner in the pack, and had to be abandoned. During 

 all these months there was no lack of time or opportunity to 

 study sea-ice in all its forms and moods, and every line of 

 Weyprecht's book is of interest to the voyager in icy seas. 

 The matter is treated quite objectively. First the different 

 forms which the ice assumes and their origin are dealt with ; 

 then ice-pressure, of which the "Tegetthoff" had sufficient 

 experience, and the nature of sea-ice in winter and in 

 summer, are described. In winter we have the formation 

 of the ice and its transformations under the combined 

 influence of .cold and varying pressure; in summer, un- 

 fortunately for the "Tegetthoff," there was no opportunity 

 of studying the disappearance of the ice, but its transforma- 

 tions under the influence of melting and varying pressure are 

 described. After these detailed studies, we have a description 

 of the motions of the ice and of the water as observed in 

 North Polar regions, and speculations as to what may be 

 expected to take place in regions not then visited. 



For the chemist and the physicist the following extracts, 



1 Die Metamorphosen des Polareises, von Karl Weyprecht. Wien : Moritz 

 Perles, 1879. 



