THE AQUAVIVARIUM. 



CHAPTER I. 



FIRST PRINCIPLES. 



ALTHOUGH it is not necessary to the practice of 

 human arts that men should be acquainted with 

 the scientific laws involved in the processes they 

 perform, yet it is admitted on all hands, that an 

 intelligent workman is better than an ignorant one ; 

 and that a man who knows the nature of the mate- 

 rials on which he has to work, will perform his 

 labour more successfully than one who does not. It 

 is on this account we think it necessary to introduce 

 our little book on the Aqua vivarium, by laying down 

 the principles on which it is constructed and main- 

 tained. Nor let any one suppose that mastering 

 these is a needless waste of time. We promise the 

 student that it will afford him instruction, illustrate 

 great laws, and save him much trouble, anxiety, 

 and expense in the management of his Aqua- 

 vivarium. 



A vessel of water containing plants and animals 

 must be looked upon as a little world ; it may, in 

 fact, be so constructed as to have no communication 

 with the great world in which it exists, and of 

 which it forms a part, and yet all its inhabitants 

 live and prosper. In order that this result may 



