4 Procoed'iiKjs. 



not think the exact specific gravity is of so much importance 

 as it is often thought to be, so long as it is near the mark. 



If you want to stock a fresh tank or bell-glass the best way 

 is to draw a portion of the water required from each of the 

 old ones, and then fill up each with some of the fresh supply. 

 This will assimilate your whole stock, and a partial transfer 

 of water from vessel to vessel is often of advantage. Above 

 all, the most scrupulous cleanliness must be observed in 

 everything connected with your tanks and glasses. Let the 

 water be perfectly clear and free from organic impurity, the 

 beach and rock-work the same, and never, if you can avoid 

 it, introduce your hand, however clean. To do so may now 

 and then be necessary, but one or two simple instruments 

 will generally obviate the need. A small net on a ring 

 of cane or wire, a slender stick for feeding (a boxwood 

 knitting-pin answers well), and a little wooden shovel fixed 

 in a long handle are the most useful implements. A glass 

 syringe is also a very valuable addition, especially in warm 

 weather ; a good syringing will aerate the water, and seems 

 to revive the flagging energies of the animals. Many of them 

 appear to thoroughly enjoy it ; probably it answers the same 

 end as the beating of the surf on the shore, in mixing a 

 quantity of atmospheric air with the water. Any animal 

 which may happen to die should be removed at once ; and, 

 should the water be contaminated, it should be withdrawn by 

 means of a syphon, and its place supplied from the reserve. 

 The foul water, if placed in a cool, dark place for a few days, 

 will again be found perfectly clear and sweet. 



"When an aquarium is thoroughly established, with a good 

 growth of conferva and a healthy stock of animals, it is best 

 to let well alone, and not to aim at too great results. 



Judicious additions may be made to the stock as occasion 

 serves, but it should always be borne in mind that it is far 

 better for your tank to be under than overstocked. 



After giving some hints as to the animals most suitable to 

 be kept, Mr. Horsnail added : — 



The temperature should never be allowed to fall much 

 below 50° Fahr., and the less it rises above 65° the better; 



