TROPICAL AQUARIUM FISHES 145 



better than none at all. but is unnecessarily severe and is not so successful, 

 as milder solutions. In fact, the strong salt takes the protective slime ofif 

 the fish and leaves it in a condition where it is liable to be quickly again 

 infected, and in a weakened condition where treatment is not likely to 

 again be effectual. The usual practice of the author is to make a solution 

 in which salt is just easily discernable to the taste. As the sense of taste 

 varies in individuals, this is not a very accurate rule to give others. A 

 suitable proportion is one ounce of salt (approximately two heaping tea- 

 spoonfuls) to each gallon of water. 



Methods of Treatment. Nearly all sick fishes do best in shallow 

 water and out of bright light. An enamel tray four inches deep by twenty 

 inches square is very good, or a well-seasoned tub filled to a few inches 

 is suitable. In placing the patient in the medicated water, see that there 

 is no considerable change in temperature. In warm weather a change to 

 very slightly cooler water is stimulating and probably does no harm. 

 Except for the air-breathing species (Paradise fish, etc.) a change to 

 several degrees warmer water is liable to produce suffocation, warm water 

 holding less free oxygen than cool. Aquarium fishes can live indefinitely 

 in the solution described, but in two days a salt solution begins to smell 

 stale and needs to be changed. A daily change is better. Should the 

 patient not show signs of improvement in four days, gradually increase 

 the strength of salt solution for two or three days until it is up to two 

 ounces (four heaping teaspoonfuls) to each gallon of water. After 

 remaining in this for two days the salt proportion is slowly weakened 

 down again to the first formula. 



Ammonia Treatment. A popular treatment among European fish 

 culturists for fungoid diseases is the ammonia method. This has not been 

 generally accepted in the United States, but has been tried with remark- 

 able success in some instances where other treatments have failed. We 

 feel, however, that it should only be tried as a last resort. To one gallon 

 of clean water add ten drops of ordinary household ammonia. (Unfor- 

 tunately, this varies somewhat in strength.) Place the fish in this for five 

 minutes, but take out sooner, should it turn over. Remove to plain water 

 and then back to its tank. The treatment may be repeated at intervals 

 of three days if necessary. 



Special Attention. All fish should, if possible, be placed, after any 

 chemical treatment, in a healthy tank containing green water. Sometimes 

 this is, indeed, the only treatment required. 



Another very good after-treatment which may be used in summer is 

 to place the hospital tank under a small stream or drip. In making the 



