THE STOCK. 263 



new ; I knew an instance in ■which a consignment of 

 animals was lost, from no traceable cause, except that 

 the water-cask, which was quite new, had been stop- 

 ped with a bung, which had been previously used in a 

 jar of some chemical solution ; yet the bung had been, 

 as was supposed, thorotighly soaked and cleansed. If 

 a cask of fir-wood can be procured it is preferable : 

 the wood of the oak, of which wine-casks are usually 

 made, gives out tannin or gallic acid, to the contained 

 water, which by its astringency converts the animal 

 integuments into leather ; if the water on coming out 

 of the cask has a brown tinge, without interfering with 

 its transparency, this is suspicious. If you cannot 

 get any other than an oak cask, let it be well seasoned 

 for two or three weeks before it be used, by filling it 

 with water (fresh or salt), changed every day. 



For smaller quantities of water large jars of stone- 

 ware are the best, being free from every objection 

 arising from liability to taint or tinge. Both casks 

 and jars can be easily sent by railway to any part 

 of the kingdom : and pure water will not spoil by 

 delay. 



THE STOCK. 



I have already entered into particulars concerning 

 the modes of collecting both plants and animals, and 

 need not repeat what may be found in the early pages 

 of this volume. A few additional observations, how- 

 ever, occur to me. 



Plants. — What are the most suitable plants for an 

 Aquarium ? Not the Oaf-weeds or Tangles {Lami- 

 naria) ; for though young specimens have an attrac- 



