18 



THE STOCK. 



sensible qualities, or in its fitness for plants and 

 animals. Since that time I have made other and 

 larger quantities, with the same success ; so that 

 I can confidently recommend the formula for general 

 adoption. The salts are sold in packets, with all 

 needful directions, by Mr. Bolton, a chymist in 

 Holborn. 



It is interesting to find that the more subtile 

 constituents of sea-water, as Lime, Iron, Silica, 

 and Iodine^ which I neglect in my formula, are 

 gradually communicated to the artificial composi- 

 tion by use. Dr. George Wilson, of Edinburgh, 

 who has analyzed portions of each of my prepara- 

 tions, after several months^ use, finds traces therein 

 of all these substances. 



It is scarcely necessary to add, that, if you can 

 conveniently procure water from the sea, you should 

 do so by preference ; si iion, Ms utere mecumJ'' 



THE STOCK. 



As I shall presently give some instructions con- 

 cerning the modes of collecting both plants and 

 animals, a few preliminary observations are all 

 that will be needful here. 



Plants. — What are the most suitable plants for 

 an Aquarium ? Not the Oar-weeds or Tangles 

 (Laminaria) ; for though young specimens have 

 an attractive appearance, they will not live long 

 in captivity ; they presently begin to decay, and 

 slough off in slimy membranous shreds, filthy to 

 look at, and hurtful to the living creatures. The 

 Fuci live pretty well, but their sliminess and 

 ugliness are fatal to their pretensions. From the 



