890 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. [12] 



were in good condition — only 5 per cent. dead. In small pail 25 per cent, 

 were dead. Temperature of water in pail 54^" F. 



No. 4. June 4 — 10 a. m. Put 100 young shad in a pint and balf of 

 water. Water stood six inches in height in jar and had surface exposure 

 of 3 inches in diameter. Placed in bottom of jar 24 scraps of sheet zinc ^ 

 inch by | inch long. All the fish were dead in thirty hours. The jar 

 was exposed to diffused daylight, and was uncorked. Chemical analy- 

 sis showed no trace of zinc in solution. Temperature of water at sta- 

 tion 70O F. 



]^o. 5. June 4 — 10 a. m. Put 100 shad under the same conditions 

 precisely as in experiment No. 4, except no zinc or other metal was pres- 

 ent. In this experiment all were alive when all were dead in No 4. 

 June 7 — 10 a. m. Only 25 fish were dead. June 13 — 10 a. m. Fish 

 have been dying very gradually for past several days. Eemoved none 

 of the dead, allowing them to drop to the bottom. June 14 — 10 a. m. 

 All dead. Temperature water used in station varying from 70° F. to 

 730 F. 



No. 6. June 4 — 10 a. m. Put 100 shad under same conditions as in 

 No. 5, except jar was wrapped and capped with ordinary writing paper 

 stained with writing ink. Fish behaved just as in No. 5, and lived 

 about as long. Could detect no difference. 



No. 7. June 4, 10 a ra. Put 100 shad under same conditions as in ex- 

 periment No. 5, except placed jar in total darkness as near as could be 

 obtained and permit presence of outside air. June 7, 10 a. m. About 

 30 per cent. dead. The remaining fish became most violently agitated 

 upon being exposed to the sunlight, some even jumping entirely out 

 of the water. June 13, 10 a. m. Fish have been gradually dying since 

 7th; only 10 are now alive, and these weak, but agitated still by the 

 light. June 14. All dead. 



No. 8. June 7. Spawn-takers at Chapman's shore took 22,000 eggs at 

 10 p. m. on 7th; put them on trays at midnight; reached hatchway at 

 1 p. m., Junes, and were put in a McDonald jar which had been heavily 

 coated with asphalt, leaving only a very small unpainted slot to observe 

 the working of the eggs. This slot was turned from the direct light 

 and covered with a flap of black paper when not ojiened to examine 

 the eggs. 



On June 12, a. m., the eggs finished hatching, producing fair percent- 

 age of fish. Fish were perfectly normal in size and development of pig- 

 ments. Thej' were afterwards placed in a separate aquarium and fed 

 on live insects. July 12. Some are yet alive and growing. 



No. 9. June 8. Placed 100 shad under same conditions as in No. 4, 

 except zinc had been previously coated with asphalt and dried for thirty 

 hours. June 10, 5 a. m. All dead. 



No. 10. June 8, 3.45 p. m. Same as experiment No. 5, except jar was 

 yesterday morning coated inside with asphalt. June 9, 10 a. m. All 

 the fish dead and jar very odoriferous of asphalt. 



