CUEING. 19 



the last few years that any other has been used. The cost of this 

 salt is very low, only about $4.25 per ton at the dock, and there is 

 no duty on that used in the curing of fish. 



Just what relation the salt bears to the reddening is not fully deter- 

 mined. It is said that the salt sometimes has a distinctly red ap- 

 pearance on the beds and in the piles while it is curing; that it has 

 been known to have a pink tint in the boat on its arrival ; that redden- 

 ing occurs in the storehouses; and also that the red color is seen on 

 the salt in the butts. We have not had an opportunity to verify all 

 these reports. The germs producing the reddening of codfish have 

 been found on the salt in storerooms and in the hold of salt vessels. A 

 large growth of germs has been observed on the wood in the walls of 

 the salt house for a distance of 2 feet or more above the floor, and the 

 germs have been taken from the salt in the butts. It is certain, how- 

 ever, that much of the so-called pink color seen on salt in bulk in 

 the hold of the vessel and warehouse is due to the breaking of the 

 rays of light, thus producing the spectra. It is equally certain that 

 the deep red color seen on the salt in the butts is due, not to the salt 

 itself, but to the growth of the germs in the organic matter which 

 has been extracted from the fish and which floats on top and makes a 

 film over the salt. In every instance in which a heavy growth of red 

 was found in a salt house it occurred on the side next to the butt 

 shed where organic matter from the butts had soaked the woodwork. 



The salts do contain calcium chlorid, magnesium chlorid, and mag- 

 nesium sulphate, which impurities affect their hygroscopic power, 

 that is, the power to absorb moisture from damp air and give it up 

 again in a drier atmosphere. This property of the dried fish is easily 

 seen in a kench, particularly in the case of hake. Water will drop 

 from the whiskers, the tails, and fins on damp cloudy days, and the 

 surface of the fish become damp and slimy. Experiments made by 

 drying the salt in an oven and then exposing it to the air show that 

 it will take up as much as 7 per cent of its weight in moisture, while a 

 refined salt will absorb only from 0.2 to 0.5 per cent. While calcium 

 and magnesium chlorid take up a great deal of water, the amount is 

 not limited to the capacity of these bodies, as the sodium chlorid, 

 which will ordinarily remain dry, will take up water when brought 

 in direct contact with it. 



One of the results of the use of a salt which is so hygroscopic is 

 that fish which have been cured and dried to any degree become moist 

 during damp weather. Fish cakes become so wet that water runs 

 from them, and boxes placed on top of each other stick together. 

 Even export fish in drums may " sweat " and need to be redried and 

 repacked. This quality makes the surface of any fish moist and thus 

 gives opportunity for the growth of such organisms as will thrive 



