AETIFICIAL SEA-WATER. 15 



accuracy was not indispensable. Scliweitzer gives 

 the following analysis of 1 000 grains of sea- water 

 taken off Brighton : — 



*' The bromide of magnesium and the carbonate 

 of lime I thought I might neglect, from the minute- 

 ness of their quantities ; as also because the former 

 was not found at all by M. Laurent in the water 

 of the Mediterranean ; and the latter might be 

 found in sufficient abundance in the fragments of 

 shell, coral, and calcareous algae, thrown in to 

 make the bottom of the Aquarium. The sulphate 

 of lime (plaster of Paris) also I ventured to elimi- 

 nate, on account of its extreme insolubility, and 

 because M. Laurent linds it in excessively minute 

 quantity. The component salts were then reduced 

 to four, which I used in the following quantities : — 



Common table salt .... 3i ounces") ^^ . , 



Tflnsnin snl+.si A I 



Epsom salts ^ » / 



Chloride of magnesium . . 200 

 Chloride of potassium . . 40 



To these salts, thrown into a jar, a little less than 

 four quarts of water (New Kiver) were added, so 

 that the solution was of that density that a specific 

 gravity bubble 1026 would just sink in it. 



" The cost of the substances was — sulph. mag. 

 Id. ; chloride mag. 3d. ; chlor. pot. l^d. ; salt, nil ; 



