70 A MANUAL 



original level is regained. If the proprietor lives at 

 a distance from the sea, and can only procure salt- 

 water at uncertain intervals, he will find that by a 

 continual system of aeration his sea- water will re- 

 main pure for a very considerable length of time. 

 If he be totally unable to procure sea-water, the fol- 

 lowing recipe (which we owe to the theory and the 

 practice of our great sea-naturalist Mr. Gosse) will 

 answer his own purposes and those of his sea- 

 anemones. Take 



Common table-salt . . 3|- ounces. 

 Epsom salts .... J ounce. 

 Chloride of magnesium 200 grains "^ 

 Chloride of potassium 40 grains J 



Add spring-water (not distilled) rather less than four 

 quarts, so that a specific-gravity bubble 1026 shall 

 just sink in it. This solution costs about 3j(i. a 

 gallon. It should be filtered before it is used for 

 the first time. When in use it should be treated in 

 the same way as sea-water, with this exception — 

 that a few plants of sea-weed (including coralline) 

 should be allowed to stand in it for some days before 

 the animals are inserted. 



When evaporation takes place to any considerable 

 extent in salt-water, it must be remembered that the 

 salt does not evaporate, and therefore, unless an en- 

 tirely new supply of water can be procured, spring 



