Fresh-rvater Aquarium. 4957 



Observations on a Fresh-water Aquarium. 

 By George Guyon, Esq. 



On a former occasion you inserted some notes I forwarded on a 

 marine aquarium of small dimensions, which I established while in 

 this island nearly two years ago. I now purpose to send you some 

 unconnected observations on a j resit- water one, maintained during the 

 greater part of the intervening period; and to this branch of the subject 

 I would wish to draw the attention of persons having a taste for Natural 

 History, as, although it is certainly inferior to sea- water aquaria in little- 

 known and curious forms, still the fresh- water establishment is very 

 interesting, and has the advantage of being attainable in any inland 

 district with the smallest possible amount of trouble : it requires much 

 less attention than its marine relative to maintain the balance between 

 animal and vegetable life for a lengthened period ; the aquatic plants 

 seem less liable to decomposition ; and the evaporation, which must 

 constantly take place from an exposed fluid surface, does not, as in the 

 case of sea-water, alter its density and change the proportion of its con- 

 stituents ; in fact, evaporation is of no consequence, as long as sufficient 

 water remains for the movements of the animals and submersion of the 

 plants. If unhealthy plants are replaced with fresh (which will seldom 

 be required), and any dead animals removed, the aquarium will con- 

 tinue in a flourishing state, under the influence of light, for almost any 

 length of time. 



I commenced the establishment on the 2 1st of August, 1854, by 

 procuring a glass gold-fish vase of two gallons capacity, and filling it 

 to about half with river water, which, up to my leaving Richmond 

 (October, 1855) has never required changing. Some sand and mud 

 obtained in the river-margin was next thrown in, together with a few 

 stones, and it was left till the next day to settle ; 1 then introduced 

 some river weeds, and at the same time procured some aquatic plants 

 from a neighbouring pond, and the live stock was commenced in the 

 shape of a common smooth water-newt and a few specimens of Limnaea 

 stagnalis and other shells ; this reptile and a specimen of Neritiua 

 fluviatilis, accidentally introduced with the river sediment, with a 

 water-beetle or two (Hydroporus), are the only aboriginal inhabitants 

 of the vase now living. The newt soon became tame enough to take 

 food offered on the point of a piece of wire, not refusing anything in 

 the shape of fish, flesh or fowl, roast, boiled or stewed; a fly would be 



