200 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



49.-PKE8ERVATION OF BAIT.* 



By P. WAAGE. 



A person engaged in the bank fisheries had requested the Danish 

 Fishery Association to give him some directions for keeping herring 

 and other small fish used as bait in a fresh condition for a considerable 

 time. As the method recommended by Mr. Waage may be of general 

 interest, and may induce some of our readers to try it on a large scale 

 and as a business, we will here describe it briefly. 



The problem may certainly be solved by filling a tin can with fresh 

 herring and pure water, and by placing this can in a freezer until its 

 entire contents are frozen solid. If such blocks of ice are put in ice they 

 may be kept for years, and the herring in them will decay scarcely at 

 all. When the air is cold enough, which however will rarely be the 

 case, the use of the freezer becomes unnecessary. 



Waage recommends that the tin cans should be square and not round, 

 so that the blocks of ice with the herring in them can be packed closer, 

 and that they should be narrower at the bottom and broader at the 

 top, so that it may be easy to extract the block of ice. The block of ice 

 will therefore get the shape of a blunt pyramid. To prevent the ice 

 from melting it will be well to make the blocks of ice large • but, on the 

 other hand, it will in many-respects be more convenient for the fisher- 

 man to use smaller cans, as, when the block has begun to melt, the her- 

 riDg should be used as quickly as possible, because they will decay very 

 soon. It is evident that the more fresh water is poured into the can in 

 proportion to the quantity of herring, the longer will the block of ice 

 keep and the herring remain fresh. 



The freezing is done by mixing three parts snow, or ice ground fine, 

 with one part common salt. It is important that both the salt and the 

 ice should be crushed very fine. The salt should be cooled off before- 

 hand. With the view to keeping this mixture as long as possible and 

 to derive the greatest possible use therefrom, it should be made in an 

 insulated vessel. This vessel should also beforehand be cooled off with 

 ice or snow. When ice and salt, properly cooled and ground fine, are 

 mixed in the above proportion, a liquid will be produced whose tem- 

 perature may fall as low as 18 degrees below zero [centigrade 1 ?]. 



The quantity of this mixture needed for freezing a certain number of 

 herring depends on the general temperature prevailing at the time, and 

 to a great degree on the manner in which the work* is done. It is, 

 therefore, impossible to state exactly how much of this mixture is 

 needed for a can of a certain size. As a general rule, the proper quan- 



*"Om Opbewaring af Agn for Mslcere." From Fiskeritidende, No. 49, Copenhagen, 

 Decembor 2, 1884. Translated from the Danish by Herman Jaoobson. 



