THE AQUARIUM. 6) 
of oxygen created in water, and the quantity con- 
sumed by aquatic animals. And it became equally 
necessary to know the means by which that supply 
was continually generated. Without the knowledge 
of these facts, and the principles by which they are 
regulated, it would have been impossible to establish 
such a marine aquarium as we may now any day 
examine in the Regent’s Park (London); where, in 
a few glass tanks, of very moderate size, we may see 
examples of some of the most curious forms of animal 
and vegetable life peculiar to the depths of the ocean ; 
forms so singular, that their first exhibition created a 
sense of wonder little less intense than that which 
must have been caused, long years ago, by the first 
public display of the mountain form of the Elephant 
to the people of cold northern countries. 
“Those principles, the knowledge of which was 
requisite to enable us thus to view the wonders of 
the Ocean in their living state in the aquarium, were 
not mastered at once, or by one man, or in one gene- 
ration. The nature of certain relations between 
animal and vegetable life, upon which they are 
founded, was first advanced by Priestley, towards the 
close of the last century, who proved that plants give 
forth the oxygen necessary to animal life. 
“ But it was not till the year 1833, that Professor 
Daubeny communicated to the British Association at 
Cambridge, a paper concerning some new researches 
prosecuted in the same direction ; while in the sum- 
mer of 1850, R. Warrington communicated to the 
Chemical Society a series of observations on the 
6 
