SUB-MARINE VEGETATION. 



87 



new, if a proper regard be paid to the success of the 

 Aquarium. 



There may, however, be circumstances in which the 

 use of actual sea-water is left temporarily out of the ques- 

 tion. In such a case, we are coerced into the choice of an 

 artificial combination which will approach as nearly to 

 the original as science may permit. The following formula 

 will be found to adapt itself to this necessity with toler- 

 able exactness, as it corresponds, with a slight exception 

 or two, to the chemical constituents of sea-water, viz. : 



Common table salt, .... 3|- ounces, 



Epsom salts, ^ ounce. 



Chloride of magnesium, . . . 200 grains, ] 



Chloride of potassium, ... 40 grains, ) ^* 



Add to these salts a little less than four quarts of river 

 water, and you will have a solution that we do not recom- 

 mend, except au pis aller, when you are unable to supply 

 yourself with the genuine article. It is confidently stated 

 that the iodine, iron, silica, lime, etc., which is found in 

 sea water will soon be communicated, by use, to the com- 

 position above given. How far this statement may agree 

 with the fact, it is not in our power to decide, as we have 

 never been placed in a position which demanded a resort 

 to such extremities. The assertion is made, however, on 

 good authority. 



Your tank fitted up,'' and the saltwater pi'ovided, 



