RIVER GARDENS; 



the aquatic plants of his tank having so perished, 

 he found the water become suddenly impure, and 

 his fish die. In this state of affairs he had direct 

 recourse to the hook of Nature for further informa- 

 tion. He examined natural ponds, in which a certain 

 amount of decaying vegetation must necessarily be 

 found, yet without causing putrefaction of the water. 

 His next step was, doubtless, to procure por- 

 tions of such decaying matter, and examine its 

 peculiar condition. It was then, we may imagine, 

 that he found the remains in question covered with 

 "Water- snails, which, acting as natural scavengers, 

 were consuming the putrescent substances as fast as 

 they occurred, and so preventing the results which 

 had proved so fatal to his tank. This was his great 

 and original discovery. He added "Water-snails to 

 his tank, and the crowning element of success was 

 achieved. Thenceforth his miniature lake went on 

 as self-supporting as its great prototypes among the 

 mountains, all the main conditions insisted on by 

 the laws of Nature having been complied with. 

 The reading of the paper containing these interest- 

 ing facts, and the publication of subsequent essays 

 on the same subject, in the "Annals of Natural 

 History," must give Mr. "Warrington the honour of 

 being the more immediate founder of the Aquarium, 



