60 THE MARINE AQUARIUM. 
some species lose their health in it, and at last perish. 
But for anemones of all kinds, many mollusks and 
crustaceans, and some other forms to be presently 
described, artificial water does well, and improves daily 
if properly managed. Unless, therefore, the aquarian is 
bent upon domesticating the rarer and more delicate sea 
specimens, he may avail himself of the aid of the chemist, 
and manufacture sea-water from the river or the pump. 
Composition of Marine Salts.—The limited space of 
this work will not enable me to enter upon the considera- 
tion of the chemistry of this question so fully as I have 
done in “‘ Rustic Adornments ;” nor, perhaps, is it neces- 
sary here to do more than point out the simplest method 
of procedure. There are at least seven ingredients besides 
water, used in the natural laboratory, but the chemist dis- 
penses with some of these, and finds every purpose served 
by using a selection of the chief of them. The composition 
of sea water is as follows :-— 
Water . : 964.744 
Common Salt, or Chloride of Sodium : 27.059 
Chloride of Magnesium é ’ 3.666 
Chloride of Potassium é : 0.765 
Bromide of Magnesium . 0.029 
Epsom Salts, or Sulphate of Mamieea 2.295 
Gypsum, or Sulphate of Lime - 1.407 
Carbonate of Lime ; ‘ x 0.033 
Loss, or not accounted for . : 0.002 
1,000.000 
Mr. Gosse, in July 1854, communicated to the “ Mag- 
azine of Natural History ” the results of experiments in 
the imitation of this composition, and a formula for the 
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