THE MARINE AQUARIUM. 55 
takes the most practical turn, has adopted this plan of 
construction, and strongly recommends it for every vessel 
intended for the reception of marine stock. Where it is 
desired to stock a vessel, in which the back plate is com- 
posed of colourless glass, with marine products, a substi- 
tute for coloured glass will be found in diaphanie; but 
the paper chosen for the purpose should be of the lightest 
shade of sea green, because it is less transparent than 
stained glass. In stocking vases, this plan of staining the 
side:next the window, is to be strongly recommended, no 
less for securing a healthy vegetation than of enlivening 
the beauty of the collection. Ihave used for this pur- 
pose, the paper and varnish prepared by Messrs. Faudel 
and Phillips, of Newgate Street, and can commend it for 
cheapness, and the ease with which it can be applied. 
Another point deserving of note is, that marine aquaria 
need a less depth of water than river collections :—For 
purposes of study, a number of glass dishes or milk-pans, 
will be found preferable to any kind of tank, or vase, 
especially for Zoophytes, though fishes and crustaceans re- 
quire more room than mere bowls would afford them. In 
fact, the lower forms of marine life may be kept for many 
months without the help of sea weeds, if placed in shallow 
vessels—the absorption of oxygen, at the surface, being 
quite equal to their demand upon the water. 
In all other respects, what has been already said on the 
subject of vessels must be understood to apply to all 
kinds of aquaria; the rectangular tank, and the bell glass, 
are the two leading forms, and to them I shall always 
refer when speaking of the tank in a general sense. 
