464 Mr. B, Waringion, [March 27, 



purpose, he proposed to lay before his audience, as far as was prac- 

 ticable, a demonstration of the principles on which it was founded, 

 particularly as very erroneous ideas had been promulgated on the 

 subject, and instructions given in several most engaging publica- 

 tions, 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 expe- 

 riments 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 dis- 

 covery of fixed air, carbonic acidU by Dr. Black, and its production in 

 respiration ; the experiments of Priestley, Ingenhousz, and Sennebier, 

 on the action of submersed aquatic vegetation exposed to light, 

 in removing carbonic acid, and restoring oxygen to the air dissolved 

 in water, — all of which had been since substantiated by numerous 

 experimenters. A cursory review was 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 preserving chara, nitella, vallisneria, 

 and other like plants in which the circulation of the sap was visible ; 

 as also for propagating 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,f 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's rays. A good healthy plant of vallisneria spiralis was 

 then transplanted, and as soon as it had recovered from this opera- 

 tion 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 very 

 material agent was required to perfect the adjustment, and render 

 it at all permanent, and which at the commencement of the experi- 

 ment had not been foreseen. The circumstances alluded to arose 

 from the natural decay of the leaves of the vallisneria, the increase 

 of which rendered the water turbid, and caused a rapid growth of 

 green confervoid mucus on the surface of the water, and upon the 



* Brande's Elements of Chemistry, 1821, and repeated up to the present 

 time. 



t Quarterly Journal of the Chemical Society, 1850. Vol. iii. p. 52, 



