368 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



of a room exhilarates and even benefits a man, while a greater increase 

 rapidly becomes injurious and fatal. 



Pure sea-water, in repeated experiments, proved fatal iu 3 hours. A 

 rapid increase of the salt, in which the supplies became all sea-water in 

 45 hours, (jar No. 1,) and the contents of the jar became S0£ per centum 

 sea- water in 60 hours, the fish showed distress and weakness, and in 

 69 hours all were dead or dying at the bottom of the jar, the water 

 having become 86.8 per centum sea-water. 



In a more slowly increasing proportion, iu which the supply became 

 all sea-water in 93 hours, (jar No. 2,) after 96 hours the water having 

 become 81£ per centum sea-water, the fish began dying. After 156 

 hours all were dead, the sea- water being .9S|- of the whole. 



In a mixture where the supply was one-half sea-water after 45 hours, 

 (jar No. 3,) and retained at that, the fish began dying when the water 

 had become 49J sea-water, or in 156 hours. In 174 hours they were 

 all dead, the mixture having become one-half (49.9 per centum) sea- 

 water. 



In the most slowly increasing proportion the supply became one-third 

 sea-water after 30 hours, (jar No. 4,) and was retained at that. The 

 fish did not begin dyiug until 177 hours, the contents of the jar being 

 one-third sea-water. After 189 hours all were dead, the per centum of 

 sea-water being 34.3. 



There seems to be sufficient in the results of these experiments to 

 deter any one from attempting to move shad across the ocean, depend- 

 ing upon the use of sea-water for large proportion of supplies; though 

 small quantities could be cautiously used for improving the stale fresh 

 water. 



The temperature experiments were not very satisfactory, as the 

 intended reductions were not readily reached and controlled with the 

 appliances at hand. In the case of No. 8, it was produced by placing 

 the jar in a refrigerator and reducing it very rapidly. The fish were 

 already six days old, and probably somewhat reduced in strength. They 

 succumbed at once to the rapid reduction of temperature, though to 

 have completed the experiment an effort should have been made to 

 revive them by gradually raising the temperature. 



No. 7 had the advantage of having fewer fish in the jar, the advan- 

 tage of a larger supply of water sustaining them beyond the expiration 

 of 5 and 6, which had about the same temperature. The indications in 

 the temperature tests are scarcely worth determining, as the devices 

 and facilities for the necessary reductions of temperatures according 

 to the plan laid down were not available, and the rapid reduction of 

 No. 8 in the refrigerator would not afford a fair comparison of endur- 

 ance of low temperatures with Nos. 5, 6, 7, 9, and 10. 



The main purpose of the series of experiments, that of testing the 

 value of sea- water, was well carried through, and I believe will be a 

 final decision against its use, except perhaps in the slight quantity 

 indicated. 



