118 REPORT OF COMMISSIONER OF FISH AND FISHERIES 
effect of this movement is araising to the surface and a crowding gradually seaward 
of the water that had in previous tides performed the part of a purifying agent. 
The strong winds of the winter season are also a factor in the circulation, as they 
take part in the annual cleansing of the Sound by either drawing in an extra 
supply of water over that brought by the tide, or forcing out water in excess of 
that taken out by the ebb flow. 
The question of fresh water brought down by the rivers and creeks has been 
ignored, because, in my judgment, it plays no essential part in the cirenlation of 
the Sound. Fresh water on reaching the sea simply slides off on the surface of the 
much denser sea water, to be carried ebb or flood with the current prevailing at the 
time. 
In regard to the current stations located on the dumping-grounds, the current 
shown, with the possible exception of those 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 waters becoming polluted. It is time, however, to 
raise in general a warning voice against what is now a common practice, and that 
is converting our rivers, harbors, lakes, and sounds into receptacles for the sewage 
and refuse of the cities and factories that line their banks. In the long run it can 
only work an injury, which as population becomes more dense will of necessity have 
to be considered and a remedy applied. 
Chemical inquiry.—Mr. Neher joined the Fish Hawk on June 9, 1890, 
and the remainder of that month was mostly occupied in perfecting the 
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, where observations were conducted incomparative security. 
The object of the investigation being simply to ascertain the 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 for determin- 
ing the amount of free and albuminoid ammonia contaived in the water, 
for which purpose itis unsurpassed by any other. Ammonia being one 
of the products of decomposition of organic substances, the determina- 
tion of its quantity in any given sample of water offers a means of 
measuring relatively the organic pollution of the same. <A few tests 
were made by the aluminium method for ascertaining the amount of 
nitrogen as nitrates and nitrites, and theratio 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 different 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 that 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 difficult to interpret his results in that 
respect. The standards followed with regard to potable water may be 
used for comparison, but it is not to be expected that such low organ- 
isms as oysters would be as readily affected by these impurities as the 
