3i8 THE AQUARIUM 



The popularity of the goldfish in the home is attested by 

 the many thousands sold yearly, at something less than popu- 

 lar prices. Conceive a glass bowl, five inches in diameter, 

 equipped with a handful of gravel and a spray of sickly 

 aquatic plant, and inhabited by two infantile goldfishes, 

 the whole offered for sale for ten cents, with a food wafer 

 or two thrown in ! Consider, also, the untimely end of these 

 unfortunates, condemned by a combination of ignorance 

 and sincere love of the beautiful. 



Yet the picture has its bright side. The amazing eager- 

 ness with which these little bowls are bought shows a wide- 

 spread desire for something alive, and only a little knowl- 

 edge, properly applied, is necessary to develop a really 

 humanizing movement. In all of the list of creatures com- 

 monly kept in the home, there is none which will thrive as 

 well, with so little care, and give so much pleasure and 

 satisfaction, as the goldfish. Once the simple principle of 

 the balanced aquarium is understood, the way is opened 

 to a vast field of interest and instruction. 



As the fish draws the water through its gills, oxygen 

 passes into the blood and, in circulating, combines with 

 waste products of the tissues, and is expelled again into the 

 water in the form of carbon dioxide, a poisonous gas. Thus 

 it is that the w^ater of tanks which are deficient in plant life 

 soon becomes vitiated and must be renewed to save the lives 

 of the inmates. But if the aquarium is supplied with grow- 

 ing plants this trouble is overcome. Carbon is exactly what 

 the plant requires for its own growth, but it has no use for 

 oxygen. Hence, having absorbed the gas through its leaves, 

 it retains the needed element and returns the oxygen to 

 the water. Thus is the water constantly kept aerated, and 

 suitable for the maintenance of animal life. An aquarium 

 of correct shape, placed in a favorable position, and stocked 

 with a suitable number of fishes and healthy aquatic plants 



