BULLETIN OF THE UNITED STATES FISH COMMISSION. 73 



to coutaiu 0.348 gram of boracic acid. The total amount of boracic acid 

 iu the two herring was therefore 1.310 grams, equal to about 20 grains. 

 Three-fourths of this acid was extracted by cooking (the acid being 

 more soluble in hot than in cold water), so that only about 5 grains 

 were left iu the tissues likely to be eaten, or about 2i grains in each 

 herring. This being the case, judging from the experiments referred 

 to above, three dozen herring preserved in boracic acid might be eaten 

 daily for months without any injury resulting from the acid taken 

 along with them. I ventured originally to call attention to the use of 

 boracic acid as a preserving agent in order, if possible, to enable the 

 herring taken off the Scottish coast to compete successfully in the 

 English markets with those sent from Norway. Hitherto, owing to 

 the ijerishable nature of herring, it has been necessary to send them 

 by fast passenger trains, which necessitates a high rate for carriage. 

 For the same reason it has been necessary, however large the take, to 

 throw the whole at once into the market, even when the supply far ex- 

 ceeded the demand. By a careful use of a mixture of boracic acid and 

 salt it is possible, with a fairly low temperature, to keep herring and 

 other small fish perfectly fresh for several days — long enough to allow 

 their being sent by slow trains, and to admit of the supply being regu- 

 lated by the demand, and prevent ijrices fluctuating from 2s. or 3s. one 

 week to 20.s-. or SOs. the next. Boracic acid has, however, many other 

 uses than this. If a curer has more fish on hand than he can sell profit- 

 ably in a fresh state, by using boracic acid he can preserve them until 

 he has an opportunity of smoking or drying them. Herring that have 

 been preserved in boracic acid make excellent bloaters. Haddock, in 

 the same way, when split can be preserved for a considerable time in 

 boracic acid before they are converted into " findons." Cod and ling- 

 may also be treated advantageously with boracic acid before they are 

 dried. The millions of dried cod found in the Bergen stores are all (as 

 the ancient and fish-like smell Indicates) undergoing, however slowly, 

 putrefactive changes. This would, to a great extent, be prevented if 

 boracic acid was used during the early stages of curing. 



Xone of the methods above referred to, however, absolutely arrest 

 putrefaction. They fail in two important respects. In the first place, 

 the organisms already in and on the fish are not completely destroyed ; 

 and, in the second place, no effective steps are taken to prevent the en- 

 trance of new organisms. At the best, it can only be said that most of 

 the original organisms are killed, while the tissues of the fish are ren- 

 dered more or less unsuitable for nourishing the surviving germs and 

 the new organisms that may be introduced. 



In preserving fish, flesh, vegetables, «S:c., the battle is with invisible 

 but ever-present organisms, which, as they live and multiply, break up 

 the organic molecules of which the tissues are composed, and lead to 

 the formation of noxious by-products. This breaking up of the tissues 

 we call putrefaction. Ju.st as the yeast plant, by breaking up grape 



