416 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



regulation of the capture of shad and herring in the Potomac 

 River, so that none shall be taken after the first day of June, 

 in any year, until the next regular fishing season, and also 

 that the hauling of the seine be prohibited on Sunday at 

 any time. JRept. Wash. Board of Health , 1874. 



EFFECT OF POLLUTED WATER OX FISHES. 



Among the various agencies injurious to fishes in fresh- 

 water streams are the waste products from gas-works, the 

 creosote and other similar substances contained therein, even 

 if in very small quantity, having a marked and destructive 

 effect; and even where the percentage is not sufficient to 

 cause death, or apparently to affect the health of the ani- 

 mals, it imparts a disagreeable taste, readily perceptible, es- 

 pecially in the case of oysters and clams, and even of fishes. 



An appeal was recently presented by the fishermen of 

 Munich to the government in reference to the admission of 

 gas-water into the River Isar, and its influence upon the 

 fishes of that stream. Professor A. Wagner, an eminent 

 chemist, was instructed to investigate the matter and make 

 a report upon it. His article has lately appeared in the JBay- 

 erisches Industrie- und Gewerbeblatt, in which he describes a 

 number of his experiments. For this purpose he introduced 

 small fishes into vessels containing well-water, different 

 amounts of gas-water being added. The results were as 

 follows : 



In water to which one per cent, of gas refuse was added, 

 the fish put into it became at once very restless, tried to 

 jump out, turned on their backs after they had been in the 

 water one minute, and were dead after the lapse of six min- 

 utes. In water containing one half per cent, of gas refuse, 

 fish became at once restless, floated on their backs after five 

 minutes, and died in thirty minutes. In water to which one 

 quarter per cent, of gas refuse had been added, fish became 

 restless after some time, floated on their backs in one hour, 

 and w T ere dead after an hour and a half. In water contain- 

 ing one tenth per cent, of gas-water, the fish remained quiet ; 

 one of them showed no change after three hours and a half, 

 but died after the lapse of six hours; no change was noticed 

 in the case of another, a small pike, after seven hours, but it 

 was found dead the next morning. 



