68 PROCKEDINGS OF SOCIETIES. 
purpose he proposed to lay before his audience, as far as was 
practicable, a demonstration of the principles on which it was 
founded, particularly as very erroneous ideas had been pro- 
mulgated on the subject, and instructions given in several 
most engaging publications, which might tend materially to 
mislead and disappoint those inclined to recreate themselves 
with this interesting subject. 
History.—After a short sketch of the several discoveries in 
the various branches of science embraced in this subject :-— 
as the experiments of Lower, Thurston, Hooke, and Mayow, 
on respiration and animal heat; the presence of air in water, 
and its necessity for supporting the life of fish, by the Hon. 
Robert Boyle; the discovery of fixed air, carbonic acid, by 
Dr. Black, and its production in respiration ; the experiments 
of Priestly, Ingenhousz, and Sennebier, on the action of sub- 
mersed aquatic vegetation exposed to light, in removing car- 
bonic acid, and restoring oxygen to the air dissolved in water, 
—all of which had been since substantiated by numerous 
experimenters. A cursoryreviewwas then given of the common 
employment of the ordinary fish-globe, the cisterns, tanks, 
pans, and tubs, with their fish and water plants, to be seen 
every day in our conservatories and green-houses, and the 
glass cylinders, used by almost every microscopist for pre- 
serving Chara, Nitella, Valisneria, and other lke plants in 
which the circulation of the sap was visible; as also for pro- 
pagating rotifers, stentors, and other microscopic animalcules ; 
the consideration of which points brought the subject up to 
modern times. Mr. Warington then proceeded to give an 
account of his own experiments, and the reasons which had 
led to their commencement, namely, the statements made for 
a series of years in our works on chemistry,* that growing 
vegetation would counterbalance the vital functions of fish. 
To test the truth of this, and its permanence,t a large twelve- 
gallon receiver was filled to about two thirds its capacity with 
river water, and some clean washed sand and gravel, with 
several large fragments of rockwork placed in it, the latter so 
arranged as to afford shelter to the fish from the sun’srays. A 
good healthy plant of Valisneria spiralis was then trans- 
planted, and as soon as it had recovered from this operation 
a pair of gold fish were introduced. The materials being 
thus arranged, all appeared to progress healthily for a short 
time, until circumstances occurred which indicated that 
another and material agent was required to perfect the adjust- 
* <Brande’s Elements of Chemistry,’ 1821, and repeated up to the 
present time. 
+ ‘Quarterly Journal of the Chemical Society,’ 1850, vol. iii, p. 52. 
