118 REPORT OF COMMISSIONER OF F1S1[ AND FISHERIES 



effect ol' this niovemeut is a raising to the surface :iii<l a crowdiiij;- gvadTially seaward 

 of the water that had in previous tides iierformed tlie i>art of a i)urifyin<r agent. 



The strong Avinds of the winter season are also a factor in the circuhitiou, as they 

 take part in the annual cleansing of the Sound by eitlier drawing in an extra 

 supi)ly of water over that hrt»ught hy the tide, or forcing out water in excess of 

 that taken out 1>y tlie ebb liow. 



The (luestion of fresli water bronglit down by the rivers and creeks has been 

 ignored, because, in my judgment, it plays no essential jiart in the circulation of 

 the Sound. Fresh water on reaching the sea siui])ly slides oft' on the surface of the 

 nnieb denser sea water, to be carried ebb or Hood with tlie current ])r(^vailing at the 

 time. 



In regard to the current stations located on the duiii])ing-grounds, the current 

 shown, with the possible exception of tliose in the towns of New Haven and Milford, 

 is not strong enough to transport the dredgings dumped on them, so that little fear 

 of the distribution of this material in the Sound need arise. 



In conclusion, the circulation of the sea in Long Island Sound seems to me to be 

 sufficient to allay all fears of its Avaters becoming polluted. It is time, however, to 

 raise in general a warning voice against what is now a conuuon ])ractice, and that 

 is converting our rivers, iiarbors, lakes, and sounds into receptacles for the scAvage 

 and refuse of the cities and factories that line their banks. In the long run it can 

 only Avork an injury, Avhich as population becomes uiore dense will of necessity have 

 to be considered and a remedy applied. 



Chemical inquiry. — ^Mr. Neher joined tlie Fish Haivlc on Jime 9, 1800, 

 and tlie remainder of that inontli was mostly occupied in perfecting tlie 

 arrangements for the chemical analyses, in preparing the reagents, and 

 in making the preliminary tests. For the convenience of this work a 

 small, temporary laboratory was constructed on the hatching deck of 

 the steamer, whereobservations were coudnctcd in comparative security. 



The object of the investigation being simply to ascertain tlie relative 

 purity of the water in the Sound, the tests applied were chiefly those 

 used to detect sewage contamination by volumetric, colorometric, and 

 gasometric methods. The Wanklyn test was resorted to ibr determin- 

 ing the amount of free and albuminoid ammonia contained in the water, 

 for which purpose itisunsur])assed by any other. Ammonia being one 

 of the products of decomi)osition of organic substances, tlie determina- 

 tion of its quantity in any given sample of Avatcr offers a means of 

 measuring relatively the organic pollution of the same. A few tests 

 were made by the aluminium method for ascertiiining the amount of 

 nitrogen as nitrates and nitrites, and the ratio of the dissolved oxygen 

 was also determined in some instances. The samples of water analyzed 

 were taken both from the surface and from the bottom in all depths 

 down to 28 fathoms, and under many ditferent conditions, as in the 

 open sound over clean bottom, on and about the dumping grounds, 

 and in some of the harbors. 



Owing to the fact (hat no standard of purity of sea water with refer- 

 ence to oysters or to the general health of adjacent land has been 

 established, Mr. Neher found it difiicult to interpret liis results in that 

 resi)ect. Tlie standards followed with regard to ])otal)le water may be 

 used for conii)arison, bnt it is not to be expected that such low organ- 

 isms as oysters would be as readily ati'ected by these impurities as the 



