940 BULLETIN OF THE BUREAU OF FISHERIES. 



they were placed in the experiment tanks of a special car and treated with 

 ozone were gradually recovering as the experiment progressed, and that at the 

 end of the ii 8 hours of the experiment the fungus growths had disappeared. 



The tench that had been used in the experiment were placed in the 

 Danube in a floating inclosure and after some four weeks were again, with some 

 carp, loaded into the special car to be carried back to Berlin. Some of the 

 tench again showed signs of fungus. The total quantity of fish used for this 

 experiment was 725 kilograms of tench, 1,500 kilograms of carp, and a few kilo- 

 grams of pike. The saturation of the water was about 50 per cent, there being 

 4,500 kilograms of water. The car reached Berlin after a journey of about 

 seventy hours, and it was found that on this occasion likewise, in spite of the 

 abnormally high saturation of the water, the growth had again disappeared 

 on the fishes and the wounds were healing. The fishes were in good condition, 

 and were kept in receptacles a long time after being unloaded. 



Experience gleaned during these experiments indicates that in the use of 

 ozone for the regeneration of water it is possible to combat the invasion of 

 fungus growth and to cure the fishes attacked by this disease. 



The method may be applied by keeping the water in which the diseased 

 fishes have to be held during their disease in constant rotation and by saturat- 

 ing it during its motion with ozone generated by dark electric discharges. 



