AQUA REGIA 



305 



AQUARIUM 



Picturing a delightful summer sport 



port for the aquaplanist, who stands upright on 

 back edge of the plane. Only experienced 

 a mere should attempt this sport, which 

 grows more and more fascinating but also more 

 dangerous as the speed of the boat is in- 

 creased, f loses his 

 balance he is thrown at once into the water. 

 :i and women enjoy this method of 

 bounding over the waves, which may have been 

 suggested by the "shoot-t he-chutes," so pop- 

 ular in pit -asure parks, or by the more pic- 

 turesque sport of the Hawaiians riding th 

 surf. 



AQUA REGIA, the name applied to a mix- 



of nitric and hydrochloric acids. Its name 



(from the Latin), meaning royal water, refers 



to its property of dissolving gold, tin- royal 



;<li'iin>t> Tin- mixture is usually 



made by combining one part of m A ith 



from tlin-r to four parts of hydrochloric. 



AQUARIUM, akwa'rium, a tank or basin 

 in which an- kept living specimens of ma: 

 or fresh- v. -as and animals. The sides 



20 



are usually const ructed of glass. No water 

 animals will live long in a vessel containing 

 only water, as the supply of oxygen, on which 

 they live, soon becomes exhausted; therefore 

 when plants and animals are put together into 

 an aquarium they help each other to live. 

 Animals inhale oxygen and breathe out car- 

 bonic acid gas. Plants inhale this gas and 

 throw off oxygen. This exchange balances the 

 life of the aquarium, as long as there are not 

 too many of either plants or animals ; too many 

 of either produces an unhealthful condition. 



The first illustration shows an aquarium of 

 simple construction which would prove of great 

 benefit to anyone wishing to study the habits 

 of water plants and animals. It must be kept 

 in a well-lighted place, as darkness promotes 

 the growth of parasites which quickly destroy 

 life. Since it has sides of glass and an open 

 top, the inhabitants can be studied from all 

 points. Kach fish three inches long requin .- 

 one gallon of water. Two or three very small 

 fish will find one gallon sufficient, but the 

 aquarium must not be overcrowded. The bot- 



AN EASILY BUILT AQUARIUM 



afford an 

 aquarium of thin nlmple construction. 



torn should be covered with an inch of clean 



nd I '1 nits .should be placed aj : 



