66 On Manufactured Sea-Water for the Aquarium. 



M. Laurent finds it in excessively minute quantity. The com- 

 ponent salts were then reduced to four, which I used in the fol- 

 lowing quantities : — 



Common table salt .... 3^ ounces. 



Epsom salts \ jj 



Chloride of magnesium . . 200 grains \m 

 Chloride of potassium ... 40 ,, j ^* 



To these salts, thrown into a jar, a little less than four quarts of 

 water (New River) were added, so that the solution was of that 

 density that a specific gravity bubble 1026 would just sink in it. 



The cost of the substances was — sulph. mag. Id. ; chloride 

 mag. 3«?. ; chlor. pot. 1^^. ; salt, nil ; — total, ^\d. per gallon. Of 

 course if a larger quantity were made the cost of the materials 

 would be diminished, so that we may set down ^d. per gallon as 

 the maximum cost of sea- water thus made. The trouble is 

 nothing, and no professional skill is requisite. 



My manufacture was made on the 2 1st of April. The follow- 

 ing day I poured oiF about half of the quantity made (filtering 

 it through a sponge in a glass funnel) into a confectioner^s 

 show- glass. I put in a bottom of small shore-pebbles, well 

 washed in fresh water, and one or two fragments of stone with 

 fronds of green sea- weed [Ulva latissimd) growing thereon. I 

 would not at once venture upon the admission of animals, as I 

 wished the water to be first somewhat impregnated with the 

 scattered spores of the Ulva-, and I thought that if any subtle 

 elements were thrown ofi^ from growing vegetables, the water 

 should have the advantage of it, before the entrance of animal 

 life. This too is the order of nature ; plants first ; then animals. 



A coating of the green spores was soon deposited on the sides 

 of the glass, and bubbles of oxygen were copiously thrown ofi" 

 every day under the excitement of the sun^s light. After a week 

 therefore I ventured to put in animals as follows : — 



2 Actinia mesemhryanthemum. Coryne ramosa, 

 7 Serpula triquetra. Crista eburnea. 



3 Balanus balanoides. aculeata. 



2 Sahella ? Cellepora pumicosa. 



2 Sabellaria {alveolata ?) Cellularia ciliata. 



2 Spio vulgaris. Bowerbankia imbricata. 



1 Cynthia {quadrangularis ?) Pedicellina Belgica. 



These throve and flourished from day to day, manifesting the 

 highest health and vigour ; the plants (including one or two Red 

 Weeds that were introduced with the animals) looked well, and 

 the water continued brilliantly crystalline. Within the succeed- 

 ing month specimens of Actinia mesembryanthemumj A. angui- 



