Salt-water or Marine Aquarium.

As the greater part of the most curious live stock of the salt-water
aquarium live upon or near the bottom, so the marine tank should be more
shallow, and allow an uninterrupted view from above. Marine creatures
are more delicately constituted than fresh-water ones; and they demand
more care, patience, and oversight to render the marine aquarium
successful.

Sea-sand and pebbles, washed clean, form the best bottom for the
salt-water aquarium. It must be recollected that many of the marine
tenants are burrowers, and require a bottom adapted to their habits.
Some rock-work is considered essential to afford a grateful shelter and
concealment to such creatures as are timid by nature, and require a spot
in which to hide: this is true of many fishes. Branches of coral, bedded
in cement, may be introduced, and form beautiful and natural objects, on
which plants will climb and droop gracefully.

Sea-water dipped from the open sea, away from the mouths of rivers,
is, of course, the best for the marine aquarium. If pure, it will bear
transportation and loss of time before being put into the tank. It may,
however, not always be possible to get sea-water, particularly for the
aquarium remote from the seaboard, and it is therefore fortunate that
artificial sea-water will answer every purpose.

The composition of natural sea-water is, in a thousand parts,
approximately, as follows: Water, 964 parts; Common Salt, 27; Chloride
of Magnesium, 3.6; Chloride of Potassium, 0.7; Sulphate of Magnesia,
(Epsom Salts,) 2; Sulphate of Lime, 1.4; Bromide of Magnesium, Carbonate
of Lime, etc., .02 to .03 parts. Now the Bromide of Magnesium, and