12 POPULAR HISTORY OP THE AQUARIUM. 



The Water. 



The great object is to get the water pure : if marine, it 

 should be taken at a distance from the mouths of rivers ; 

 that dipped in mid-channel is preferred b}^ professed Aqua- 

 rianSj although I cannot tell exactly why. I should have sup- 

 posed that water taken from the shore, Avhence the greater 

 part of the specimens are procured, would be most likely 

 to contain those materials which were most suitable for their 

 support. Artificial sea-water is now much used, and the 

 formula for its preparation is given by several authors. 

 But I do not advise the uninitiated to experiment in its 

 composition. Aquarium dealers sell tlie necessary powders, 

 mixed in proper proportions, and will give full directions 

 for its use. 



It is evident, however, that the artificial water must be 

 at first totally deficient in one very important element, 

 namely, the animalcules with which water in its natural 

 state abounds, and which are necessary for the sustenance 

 of many marine animals. These must be introduced by 

 the insertion of seaweeds, and time must be given for them 

 to act beneficially on the water. Bright and clear river- 

 water is best for fresh Aquaria. 



