How to obtain it. 241 
the latter case the fish should not be returned to their pond, but 
be placed in another small one by themselves, so that the dose 
can be repeated where the first is not efficacious. It should be 
borne in mind, in putting salt through the ponds, that it is 
destructive to some forms of life, and there is a danger of its dis- 
arranging the equilibrium of life in the water, which has an 
important bearing on the welfare of the little fish. The salt bath 
after removal from the ponds is the best remedy. The solution 
may vary in strength. The weaker it is the longer the fish can 
remain in it, and the stronger it is the sooner they require removal. 
I prefer a moderately strong dose of salt, though by no means in 
excess, but different practitioners have such varied opinions as to 
the strength of the liquid required, that I would advise the 
beginner to try a few experiments with a small number of fish at 
first, and then decide as to the best course. A very strong dose 
destroys the fungus, but time is required, and if the fish turn 
sickly at once and have to be taken out, the liquid may not have 
had time to saturate the fungoid coating, and so the desired 
object will not be attained. A milder dose is often more efficacious, 
the fish remaining longer in it. The signal for taking them 
out is their coming to the surface or going over on their sides, 
when they should be at once removed to a current of good water, 
which will soon revive most if not all of them. Of course a few 
will die, as may be reasonably expected in the case of such delicate 
little creatures, but in skilful hands the death-rate should be com- 
paratively small, and sometimes it is almost wz/. Sea water is 
better than salt and water where it can be readily obtained. 
As the season advances, and the little fish grow, the quantity 
of food will require increasing, and when the death-rate is low 
they will soon require thinning out. For this purpose it is 
necessary to have some extra ponds, and they may be a good 
deal larger than the nurseries. A pond about sixty feet long and 
sixteen or twenty feet wide, with water four feet deep, will do very 
well, and if in autumn the level can be raised to six feet so much 
the better. If the fish are not thinned out they are very liable 
to contract disease and die. Some of them that have grown 
faster than the rest will also become cannibals and devour their 
fellows. The pollution of the water by being breathed over by so 
R 
