14 ARTIFICIAL SEA-WATER. 



If the water on coming out of tlie cask has a hrown 

 tinge, without interfering with its transparency, 

 this is suspicious. If you cannot get any other 

 than an oak casii, let it be well seasoned for two 

 or three weeks before it be used, by filling it with 

 water (fresh or salt), changed every day. 



For smaller quantities of water large jars of 

 stone-ware are the best, being free from every 

 objection arising from liability to taint or tinge. 

 Both casks and jars can be easily sent by railway 

 to any part of the kingdom ; and pure water will 

 not spoil by delay. 



Artificial Sea-water. — In July, 1854, 1 pub- 

 lished the following communication in the "Annals 

 and Magazine of Natural History." 



On Manufactured Sea Water for the Aquarium: 

 — " The inconvenience, delay and expense at- 

 tendant upon the procuring 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 manu- 

 facture 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. . . . 



" 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 



