Taylor. — Preservation of Fish by Salt 147 



also that for other reasons salt free from impurity is better. 

 The results on reddened cod only emphasize this advice. 



The research on reddening should not, however, end here. 

 We are, again, dealing with questions of permeability. The 

 bacteria are adjusted to strong salt solutions, that is, the body 

 fluid is of such concentration and their covering membrane is 

 of such partial permeability that when surrounded by strong 

 salt solution they live normally, but when water or weak brine 

 surrounds them, these relations are disturbed and they die. 

 Probably water enters the cell in excessive quantity. It is 

 known that the reddening does not attack fat fish. Perhaps 

 the fat acts directly on the membrane, or indirectly by acting 

 on the calcium and magnesium in the salt, to effect the dis- 

 turbance. 



RECOVERY OF BRINE 



Even crude salt now costs considerably more than coal. 

 Yet the fish packers who are usually very careful to economize 

 coal are prodigal in the use of salt. Every hundred pounds 

 of brine that goes overboard contains about twenty-five 

 pounds of salt, to say nothing of the valuable nitrogenous 

 matter that the brine extracted from the fish. Considerable 

 work has been done by the writer and his associates on the 

 development of a process to recover salt and other substances 

 of value from old pickle. A trial plant has been in use and 

 under observation at an important fish packing establishment 

 for over a year, but has not reached a satisfactory stage for 

 publication of details. Brine pure enough for use is recov- 

 ered, while a substance very rich in nitrogen is yielded as a 

 by-product. This substance in the dry condition is nearly 

 white and friable and contains enough nitrogen to command 

 a handsome price as fertilizer, if suitable for that purpose; 

 but there are other uses of it under consideration for which it 

 may be more valuable. The method being tried recovers 

 brine; for this reason some other method that would produce 

 dry salt may be better. In any event, this promising subject 



