64 A Retrospect of Oceanography 



in the well-known form of gypsum, the crystals being all alike, and there 

 being no amorphous matter amongst them." 



Haeckel relied chiefly on its faculty of being stained by 

 carmine as evidence that the body which he was examining 

 was organic. Sulphate of lime as prepared by the precipitation 

 of an aqueous solution of a calcium salt by alcohol is a perfectly 

 amorphous flocculent precipitate which is coloured intensely 

 by carmine, and the colour is fast as against treatment with 

 spirit. The naturalists on board had great difficulty at first 

 in believing that this reaction was not, as Haeckel thought 

 it was, absolutely decisive of the organic character of the body. 



To remove this view, however, it was only necessary to 

 point out that the production of pigments by the staining 

 of amorphous mineral precipitates with organic colouring 

 matters was a very old chemical industry. The pigments 

 so produced are called by the generic name of Lakes ; and the 

 mineral precipitate most commonly used is hydrate of alumina ; 

 but many other substances can be used for the purpose, and 

 it appeared that sulphate of lime when freshly precipitated 

 by alcohol was to be added to the list. 



Huxley, the discoverer of Bathybius, frankly acknowledged 

 the mistake which had been made; Haeckel, who adopted 

 Bathybius, ceased to use the word. 



I have dwelt at considerable length on these two doctrines 

 relating to the conditions at the bottom of the ocean, namely 

 that of the continuity in time of the chalk and that of the 

 continuity in space of organic plasma, not only because they 

 characterise the views held by leading naturalists between 

 the years 1868 and 1873, but also because the proving of these 

 doctrines was the immediate motive of much of the early 

 work done on board the "Challenger." That the result showed 

 that it was impossible to uphold either doctrine, diminishes 

 in nothing the usefulness of their having been put forward 

 as hypotheses, nor does it afford any reason for their being 

 allowed to pass into oblivion. 



The waters of different localities of the ocean are dis- 

 tinguished by the amount and nature of the saline matter 

 dissolved in them. It has been found that the nature of the 



