AHVASum. 



that an aquarium sliould be loaded with roekwork, and thii^ 

 that fantastic arches and minarets of Soman cement add to 

 the beauty of the tank. If the vessel be very large, then a few 

 irregular blocks of stone may be introduced with a good effect ; 

 but in a small tank we should recommend the exclusion of 

 roekwork altogether, as it takes up a great deal of room that 

 cannot be well spared, and unless it be very tastefully managed 

 has a childish and ridiculous appearance. We need scarcely 

 caution out readers against admitting sea-shells, branches of 

 coral, plaster images, and other mantel ornaments into a fresh- 

 water aquarium, though we have seen such a violation of taste 

 perpetrated again and again. An aquarium should be made 

 to imitate nature as closely as possible, and as we neither find 

 cowries, corals, nor busts of Napoleon in our brooks and ponds, 

 we have no right to introduce such objects in our tanks." 

 Gilbert White had occasion to animadvert upon a very similar 

 barbarity practised by certain keepers of gold fish in his day. 

 " Some people," he says, " exhibit this sort of fish in a very 

 fanciful way, for they cause a glass bowl to be blown with a 

 large hollow space within, that does not communicate with it. 

 In this cavity they put a bird occasionally, so that you may see 

 a goldfinch or a linnet hopping, as it were, in the midst of the 

 water, and the fishes swimming in a circle round it. The 

 simple exhibition of fishes is agreeable and pleasant, but in so 

 complicated a way becoines whimsical and unnatural." 



Before we proceed to describe the sort of plants that thrive 

 best in the aquariuin, besides looking handsomest and giving 

 least trouble, it will be as well to explain why the presence of 

 vegetable life is necessary to the very existence of your scaly 

 pets. Indeed it was this necessity that led to the invention of 

 the aquarium. Mr. Warrington was the first to draw public 

 attention to the subject. He says : — " My attention was first 

 drawn to the subject early in the year 1849. The speedy 

 death of some gold fish that I had in a glass globe attracted 

 my attention, and which, on experiment, I found was caused 

 by the want of oxygen gas, a fresh supply being constantly 

 required for their support ; and also to the existence of a large 

 quantity of carbonic-acid gas, which was given off during the 

 respiration of the fish. What, therefore, was required was, 

 something from which a supply of oxygen could be obtained, 

 and which would also absorb or consume carbonic-acid gas. I 

 found that aquatic plants were just what I required. I there- 

 fore commenced my farther experiments in May of the same 



