J. PISCICULTURE AND THE FISHERIES. 429 



smell that cod-liver oil sometimes exhibits is from the min- 

 gling of very minute pieces of the liver with the oil, which 

 afterward putrefy in it. After being skimmed off, the oil is 

 boiled until the water is evaporated. 



The next operation is that of filtering, which is continued 

 at least four times, the last filter being of the finest muslin, 

 which extracts all traces of sediment. The resultant liquid, 

 provided the livers were not more than twelve hours old, 

 resembles Sauterne wine in appearance, and is almost entire- 

 ly devoid of color, taste, and smell. 



The usual yield of oil is given as about one gallon to the 

 quintal of livers. Owing to the low temperature at which 

 the oil is extracted, fifteen months is the longest time it will 

 keep sweet and retain its original flavor ; after that time va- 

 rious ingredients are mixed with it which preserve it, or 

 rather disguise its rancid taste. 



In some localities in America the process of steaming is 

 resorted to, which is supposed to facilitate the operation 

 and improve the product. 



OPERATIONS OF THE UNITED STATES FISH COMMISSION IN 



1875. 



The operations of the United States Fish Commission for 

 the year 1875, so far as the hatching and distributing of 

 shad were concerned, closed at the end of July, after a very 

 successful season. The work was commenced in April, on 

 the Neuse, in North Carolina, and continued subsequently 

 on the Pamunky, the Rappahannock, the Potomac, and the 

 Delaware ; but, owing to the extremely small run of shad 

 in these streams, very little was accomplished. With the 

 assistance of the New York State Commission, a small sup- 

 ply of young shad was obtained at Castleton, on the Hud- 

 son ; but even here the run of shad was very poor, being 

 much below that of previous years. The indifferent luck of 

 the season was, however, changed after commencing opera- 

 tions at Holyoke, on the Connecticut, about the 1st of July, 

 where, under the direction of Mr. James W. Milner, the As- 

 sistant Fish Commissioner, a very extensive hatching and 

 distribution was initiated, the work extending satisfactorily 

 throughout the month. Here the entire expense of hatch- 

 ing and distribution was borne by the United States, the 



