12 American Fisheries Society 



of the product. Sodium chloride (common salt) penetrates the 

 fish very rapidly and completely. Small amounts of calcium 

 chloride, magnesium chloride or sodium sulphate added to the pure 

 brine retard penetration. It may thus be seen how such impurities 

 may adversely affect the proper preservation of fish in hot weather 

 by prolonging the time of penetration until after decomposition 

 has set in. As to quality of fish, pure salt produces a soft, more 

 flexible meat, brownish or grayish in color. Calcium salts, which 

 occur in commercial salts in sufficient quantities to affect the 

 quality, retard penetration more than do magnesium or sulphur 

 salts and cause the most noticeable whitening and hardening of 

 the tissues. The investigation has also shown that salt penetrates 

 the cut flesh of fish twice as rapidly as it penetrates unskinned fish. 



By exercising unusual care in removing all blood and viscera, 

 including roe and milt, and soaking the fish for thirty minutes, the 

 investigator salted river herring at a temperature above 88° F., 

 while the highest safe temperature at which salting may be done 

 by methods in common practice is 60° F. Experiments indicate 

 that the blood spoils at a temperature at least 25° F. lower than 

 the spoilage temperature of the flesh of the fish. In the practical 

 application of these methods it appears that the removal of all 

 blood and viscera, including roe and milt, may have an important 

 bearing in solving the problem of salting fish in warm climates. 

 An investigation of the chemical changes taking place in the fat 

 and protein of the fish during storage is in progress. As yet 

 opportunity has not been afforded for the practical application 

 of these results to determine in what ways they may be made to 

 .serve the industry. 



Brine recovery.— Because of the usual practice of discarding 

 used brine employed in the salting of fish, much salt has been 

 wasted. The possibilities of producing better fish by the use 

 of high grade salts as indicated above and the high cost of refined 

 salts, make economies in the use of such salts imperative. For 

 these reasons, during recent months attention has been given to 

 the development of a process for the recovery of used brine, 

 with such success that it now appears that it will be a practicable 

 economical procedure. In this process, advantage has been taken 

 of the adsorption of exceedingly fine precipitated particles of 

 tasteless and inert matter which carry down most of not only the 



