LOSS OF WHALES BY SINKING. 59 



cutting him in, proved to be a dry-skin that 

 is, the blubber containing much of a milky 

 fluid instead of oil, and yet the whale floated 

 " quite light." Again, he has killed a whale 

 with a single lance, which sunk like a stone, 

 whilst another, after lancing a hundred times, 

 likewise sank.* 



An ingenious Frenchman, I am told, in 



* The tendency of the whales killed in tropical climates to 

 sink after death, admits, perhaps, of the simplest explanation 

 on the supposition that the ordinary specific gravity of the 

 animal is hut very little less than that of sea- water. Hence in 

 the Arctic regions, where the specific gravity of the water is 

 increased by a freezing temperature, the cases of sinking are 

 very unusual ; whilst the same description of animal, being 

 immersed in water 30 to 50 warmer, might, from the effects 

 of temperature alone, become ordinarily of a specific gravity 

 so nearly the same as that of the supporting element as some- 

 times to sink, sometimes to swim. 



But to illustrate the extent of this influence of tempera- 

 ture : The mean specific gravity of the Greenland Seas, as 

 shown in Scoresby's Arctic Regions (vol. i., p. 182, 183) is 

 1-0265 at the temperature of 60. This density, reduced to 

 the freezing temperature, would be 1*0281, or to a tropical 

 temperature (80) 1'0243. The difference, in its effect on the 

 Imoyancy of a full-grown whale of 50 tons weight, would be 

 about 4 cwt. ; that is, a whale with a floating power of less 

 than 4 cwt., in the Arctic regions, would, in a sea of like salt- 

 ness of a tropical temperature, sink. 



It has been ascertained, however, by the above authority, 

 that the icy seas of the north are somewhat less salt than those 



