AILMENTS AND DISEASES 



intervals until by evening all has been introduced. After about two-thirds 

 of the solution has been added, careful attention must be given to the fish, 

 and if its condition is weak and the indications are that it would be endangered 

 by a stronger bath, it should be removed to the second vessel, the water of 

 which has been aerated by frequently dipping out and pouring back. It 

 is necessary to leave the fish in the solution as long as endurable without 

 complete exhaustion indicated by excessive restlessness and later by partly 

 or completely turning on its side. Should the fish not recover at once in 

 the second vessel, it must be kept in motion by gently stirring the water. 



Picric acid has also been found to be beneficial. A one-percent, 

 solution of this poisonous acid is made in hot water. The fish is placed 

 in well-aerated water to which small quantities of the solution are added, 

 until 1^ to t;^ part of the acid is present in the water, if the fish can endure 

 this amount, and then, after a few minutes, water of the same temperature 

 is added at intervals until a very considerable dilution has taken place, when 

 the fish should be removed to well-aerated water. This may be repeated 

 after a few days, the fish to remain in the weakened bath several hours, if 

 possible. Chlorate of potassium is used in the same manner, but the 

 amount present in the water should hot exceed i in looo. All three of 

 these remedies are certain to destroy the higher forms of surface parasites, 

 and usually those encysted on the fish. 



American breeders have successfully applied the following remedies, 

 all of which are to be recommended: — 



Permanganate of potassium solutions are powerful disinfectants and 

 frequently used specifics, but are not, always efficient. They produce an 

 objectionable discoloration of the water and when sufficiently strong to 

 destroy the parasites cannot be endured by the fishes. The best applica- 

 tion is by the use of a separate vessel, and covering the mouth and gills 

 of the fish with a wet cloth agitating the body in a strong solution for a 

 few minutes, then placing the fish into water to wash off the potassium 

 before returning it to the hospital jar. 



Bichloride of mercury has been found to be beneficial when applied 

 in the same manner, also a weak solution of formalin; a tablet of the former 

 in a pint of water and a lo percent, solution of the latter. Salt is a gener- 

 ally applied and safe remedy, and should be used as previously mentioned, 

 a strong solution kept from the gills, and a weaker one by placing the fish 

 into it for one or more days. 



External applications of boracic acid in water have proven effectual 

 for surface parasites, and should be frequently applied with a brush or a 

 pledget of cotton. Very satisfactory results have been obtained with a 

 50 percent, solution of peroxide of hydrogen in water. The fish is grasped 



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