lived until 6 p. m. on the 22d, an additional period of 

 hours, making a total of 181 hours. 



Scheme II. — (Jar No. 2): To change from spring 

 water to sea water in 90 hours, adding one-half a sill of 

 sea water at each change. This scheme was completed 

 on the 19th, at 3 p, m. The temperature ranged from 

 66° to 70°, except on the 20th, when at 6 p. m. it reached 

 78°, that of the air being 79 Q ; this no doubt, hastened 

 the death of the young shad which showed signs of 

 weakness on the 19th. at 9 p. m., gradually dying from 

 tr~t tiuiv- until 9 a. m. on the 22d. when all were gone, 

 172 hours after leaving the hatching boxes, and 66 hours 

 after the water had become entirely salt. 



Scheme III. — (Jar No. 3): To change the water in 36 

 hours from spring water to a mixture of one-third sea 

 water and two-thirds fresh water; adding one-half a gill 

 of sea water at every change. This scheme was com- 

 pleted on the 17th, at 9 a. m. The temperature ranged 

 from 66° to 68° on the 20th and 23d rising with the air 

 at high as 75°, and this excessive heat caused consider- 

 able mortality. On the 23d at 6 p. m. they showed signs 

 of debility, yet on the 24th at 3 p. m. fully one-eighth 

 were alive, and some survived until 7 p. m. on the 25th 

 252 hours after leaving the hatching boxes and 174 

 hours after their water had been changed to the required 

 proportions. 



Scheme IV. — (Jar No. 4): To change the water in 45 

 hours to a mixture of spring and sea water in equal 

 parts; adding one-half a gill of sea water every three 

 hours; This scheme was completed on the 17th, at 

 6 p. m. The fish in this jar seemed exceptionally 

 sprightly until they beean to settle on the bottom at 

 9 a. m. on the 23d; all w T ere dead at 3 a. m. on the 23d, 

 190 hours after leaving the hatching boxes and 129 hours 

 after their water was brought to its required propor- 

 tions. 



Scheme V. — (Jar No. 12): To change the fishes di- 

 rectly from spring water to sea water. This experi- 

 ment was repeated three times, the fishes dying in from 

 two to three hours. 



Scheme VI. — [Jar No. 13]: To keep the fish in wa- 

 ter dipped from the surface after a heavy rain. The 

 water was very brackish, and its temperature ranged 

 from 69 ° to 72 ° . The fish lived from 8 a. m. on the 

 16th to 12 m., on the 21st, 124 hours. 



Scheme VII. — [Jar No. 14] : To change from Jar No. 

 14 to fresh spring water. This change was effected at 

 5 p. m. on . .ie 2id, and the fish survived until 9 p. m. 

 on the 23d 



