On Manufactured Sea- Water for the Aquarium. (55 



VI. — On Manufactured Sea-Water for the Aquarium. 

 By P. H. Gosse, A.L.S. 



The inconvenience, delay and expense attendant upon the pro- 

 curing of sea-water, from the coast or from the ocean, I had 

 long ago felt to be a great difficulty in the way of a general 

 adoption of the Marine Aquarium. Even in London it is an 

 awkward and precarious matter; how much more in inland 

 towns and country places, where it must always prove not only 

 a hindrance, but to the many an insuperable objection. The 

 thought had occurred to me, that, as the constituents of sea- 

 water are known, it might be practicable to manufacture it; 

 since all that seemed necessary was to bring together the salts in 

 proper proportion, and add pure water till the solution was of 

 the proper specific gravity. Several scientific friends to whom 

 I mentioned my thoughts, expressed their doubts of the possi- 

 bility of the manufacture ; and one or two went so far as to say 

 that it had been tried, but that it had been found not to answer ; 

 that though it looked like sea-water, tasted, smelt, like the right 

 thing, yet it would not support animal life. Still, I could not 

 help saying, with the lawyers, " If not, why not ?" 



Experientia docet. I determined to try the matter for myself. 



I took Schweitzer's analysis ; but as I found that there was 

 some slight difference between his and Laurent's, I concluded 

 that a very minute accuracy was not indispensable. Schweitzer 

 gives the following analysis of 1000 grains of sea-water taken off 

 Brighton : — 



999-998 



The bromide of magnesium and the carbonate of lime I 

 thought I might neglect, from the minuteness of their quanti- 

 ties; as also because the former was not found at all by M. Lau- 

 rent in the water of the Mediterranean ; and the latter might be 

 found in sufficient abundance in the fragments of shell, coral, 

 and calcareous algse, thrown in to make the bottom of the aqua- 

 rium. The sulphate of lime (plaster of Paris) also I ventured to 

 eliminate, on account of its extreme insolubility, and because 



Ann. §■ Mag. N. Hist. Ser. 2. Vol. xiv. 5 



