188 



BULLETIN OF THE UNITED STATES FISH COMMISSION. 



In most of the experiments given below, it will be noticed that the solutions bad 

 little or no effect upon the parasites, or that the fish were affected in so short a time 

 that it was impracticable to experiment further with the solutions named. Constant 

 aeration was employed. 



18. Peroxide of hydrogen (H. 2 2 ), 1 cc. ; lake water, 



400 cc. 



19. HO. 2 cc. Sat. salt sol., 3 cc. ; lake water, 



1,000 cc. 34°C. 



20. HO*, 1 cc. Sat. salt sol., 1 cc. ; lake water, 



500 cc. 24.8° C, 4:11p.m. 

 • 4:42 H a 2 added, 3 cc. 



4:45 Sat. salt sol., added, 3 cc. 



4:54 Sat. salt sol., 2 cc. 



5:00 H s Oj, lcc. 



5:02 Hs0 3 , lcc. 



5: 15 Sat. salt sol., 1 cc. 



21. * Ker. einul., 100 cc. ; lake water, 400 cc. 



22. Kerosene emulsion, 666 cc. ; lake water, 1000 cc. 



23. Kerosene emulsion, 100 cc. ; methylen blue, 



4 cc. ; lake water. 900 cc. 23° C. 



24. Ker. emul., 50 cc. ; lake water, 500 cc. 23° C. 

 11 : 39. Methylen blue, 1 cc. 



25. Kerosene emulsion, 30 cc. ; lake water, 500 cc. 



26. Kerosene emulsion, 500 cc. 



Small trout overcome in 17 minutes; parasites 

 were unaffected. 



Small trout lived 1 hour and then gradually weak- 

 ened ; parasites were unaffected. 



4:11. Small trout. 



4 : 48. Small trout. 



5:16. Both fish slightly overcome but revived in 

 water. Parasites on fish alive. Considerable 

 scum had fallen from the fish and those proto- 

 zoa which fell from the trout were killed. 



Small trout overcome in 3 minutes, recovered in 



water. Parasites unaffected. 

 Small trout overcome in 22 min., revived in 



water. 

 About half the parasites and considerable scum fell 



from fish, but the protozoa were unaffected. 

 Small trout overcome in 2 minutes, revived iu 



water. Parasites unaffected. 

 10 : 36. Small trout. 



11:51. Some of the scum had fallen from trout. 

 12 : 10. Trout slightly overcome ; revive in water. 

 12:20. Trout replaced in the solution. 

 4:00. Still alive. Parasites on fish and in water 



were unaffected. 

 Fish and parasites were unaffected after 3 hours ; 



some of the scum was removed. 

 (a) Trout overcome in 2 minutes. 

 (6) Trout alive and well after 1 hour. Parasites 



unaffected. Some scum had fallen. 



Kerosene cleans the fish to some extent, but has little or no effect upon the proto- 

 zoa. The individual fish are affected very differently by the emulsion. 



27. Creosote, 1 drop; lake water, 200 cc. 



28. Creosote, 1 : 800 1 cc ; lake water, 300 cc 



29. Vinegar 1 cc. ; lake water, 200 cc. 

 12:35. Vinegar added, 1 cc. 



30. Vinegar, 15 drops; lake water, 105 cc. 



31. Salycilic acid, |- gram ; lake water, 200 cc. 



32. Permanganate of potassium, 1 minute crystal ; 



lake water, 700 cc. 



33. Chlorinated soda soi., 2cc; sat. salt sol.,5cc; 



lake water, 1,000 cc. 



34. Same as No. 33. 



35. Tannic acid, 1 cc ; lake water, 500 cc. 



36. Chi. soda sol., 2cc; salt sat. sol., 5 cc; lake 



water, 500 cc. 



37. Same as No. 36. 



38. Seller's tablets, 2 ; lake water, 2,000 cc. 

 3:45. Seller's tablets, 2. 



39. Ferrous sulphate (copperas), small crystal; 



lake water, 2,000 cc. 



Trout overcome in 2 minutes but recovered in 



water. Parasites unaffected. 

 Fish dies in 8 min.. parasites alive at end of 3hrs. 

 12 : 30. Small trout. 



2: 00 p. m. Trout died, parasites alive. 

 Trout affected immediately; free parasites die 



in 2 miuutes. 

 Trout dies in 4 minutes ; parasites unaffected. 

 Trout lives 2 minutes ; parasites unaffected. 



Small trout died in 3 minutes; parasites unaf- 

 fected. 



Same result. 



Trout unaffected after 1 and 1-J hours ; parasites 

 unaffected. 



Trout overcome in 3 minutes; parasites alive. 



Trout overcome in 2 minutes; parasites alive. 



12:55. Small trout. 



4:23. Fish partially overcome; parasites on fish 



alive, those in the solution dead. 

 11:43. Catfish. 



3p.m. Fish dead; parasites in solution dead, 

 those on the fish still alive. 



' Two parts kerosene to 1 part milk. 



