33 



minerals or other substances that mla:ht prove injurious. If there 

 is no rockwork above the surface, a floating island may be intro" 

 duced, a piece of cork may be carved to suit the fancy, after which 

 it should be burned all over the surface to give it a unique appear- 

 ance. If the size of the "island " will admit of it, holes may be 

 made through it, and some of the plants can be trained up through 

 these holes: the plants will, to the casual observer, appear to be 

 growing on the island ; or the surface of the island may be hoi. 

 lowed out in places and filled with soil. Ferns and other small 

 plants will grow admirably therein ; the soil'inay be raised to 

 represent small hillocks. After what we have said about imitating 

 nature we hardly think it necessary to say that coral and Marine 

 shells should not be introduced into a fresh water acquarium ; and 

 here permit us to say that salt water fish or plants will not flour 

 ish in fresh water, nor will the inhabitants of fresh water live in 

 salt water. The water for use in an aquarium should be clear as 

 crystal, and great care must be exercised that it be free from 

 saline matter or the result may be very serious. It should be ob- 

 tained from a river or brook ; if, however, there is no such stream 

 in the neighborhood, spring or rain water must be used. The latter 

 is decidedly preferable, but before it is used it should be filtered 

 to render it perfectly clear. If spring water must be used it should 

 be allowed to stand in the open air in a tub or some other such vessel 

 for a few days in order to be softened by the action of the elements. 



When an aquarium is provided with plants and animals, In 

 proper proportion, changing the water will be found quite unneces- 

 sary. The plants will consume the carbonic acid gas given oflfby 

 the animals, and for this will return to the water in which they 

 live, the oxygen necessary for the maintenance of animal life. It 

 is frequently necessary to aerate the water ; this should be done 

 whenever the fishes come to the surface for the purpose of gulping 

 air. It can be done by supplying a portion of fresh water, or by 

 introducing oxygen (air) by an artificial process. The simplest 

 way to do this is to take out portions of w-ater and then pouring 

 them in again from a small height, say from two to three feet. 

 When a fountain can be introduced no other mode of aeration 

 will be needed. The temperature of the water should not be more 

 than seventy nor less than fifty degrees ; the mean temperature^ 

 sixty degrees, will prove the most suitable. 



Plants and Pi.akting. By reference to the latter part Of 

 this book you will discover those plants which require the 

 most water. From these select those which, when grouped in 



