THE SALTING OF FISH. 



27 



sulphates found in commercial salts would have any appreciable 

 effect on the penetration of salt in fish. 



SUMMABY. 



1. Small amounts of calcium chloride or magnesium chloride, as 

 impurities in salt, retard the penetration of the sodium chloride into 

 the squeteague. 



22 

 20 

 18 

 16 

 14 

 12 

 10 



1 



6 



9 



10 



Fig. 3. — Curves show retardation of penetration of salt due to 4.7 \nn- cent of magnesium 

 chloride impurity (section one-half to 1 cm. depth). Figures at left indicate per cent 

 of chlorine in dry fish ; at bottom, time in days. 



2. The sulphate ion has a similar, though less noticeable, effect. 



3. Calcium chloride and magnesium chloride, as impurities in salt, 

 cause a firmer, whiter fish than pure sodium chloride. 



INFLUENCE OF IMPURITIES ON RATE OF PROTEIN DECOMPOSITION." 



INTRODUCTION. 



When the consideration of obtaining the relative values of different 

 methods of salting fish was first taken up, the rate of penetration of 



"The analytical work reported in this section of the paper was done by J. F. Stephl, 

 temporary assistant. U. S. Bureau of Fisheries. 



35286= 



-15 



