Taylor. — Preservation of Fish by Salt 133 



may imagine that a new dilute film forms again very rapidly. 

 If, instead of brine, dry salt is placed in contact with the fish, 

 very material differences are at once apparent. Part of the salt, 

 dissolving in the free moisture, forms strong brine which 

 begins its extraction of water from the cell. The water coming 

 from the cell is not able to dilute the adjacent brine, because 

 some of the excess of dry salt present immediately dissolves 

 and thus assures saturated brine at all times. It should also be 

 obvious that since the very purpose of using salt on fish is to 

 extract water, the addition of water to begin with simply sup- 

 plies just so much water to the salt and satisfies the affinity of 

 salt for water to that extent. The water should come from the 

 fish and not elsewhere. 



To put the conclusions from this section of the paper into 

 words, when salt is applied dry to the fish, there is a more rapid 

 penetration of salt, less decomposition of fish, and it is possible 

 to preserve fish at a higher temperature ; the superiority of dry 

 salt over brine resides in the fact that the brine in contact with 

 the fish is not permitted to be diluted when salt is present in 

 crystalline condition. 



OTHER FACTORS THAT AFFECT PERMEABILITY 



While no investigations appear to have been made on the 

 influence of temperature on the permeability of fish flesh, inves- 

 tigations have been made on a great variety of other living 

 things, so that it is probably safe to generalize cautiously 

 regarding such influences on fish. Osmotic pressure varies, 

 approximately, as absolute temperature.* That is, if we double 

 absolute temperature, osmotic pressure is doubled, other factors 

 being held constant. The range from freezing to 100° F. 

 within which fish salting is usually done is, on the absolute scale, 

 rather narrow (491.4° to 559.4° A.), so the maximum variation 

 due to this cause would be about 14 per cent. It is, however, 

 a common experience in pickling fish that the warmer the tem- 



*Absolute temperature; is based on absolute zero, the point of no heat, or absolute 

 cold, which is — 273° C. or — 459.4° F. If we use degrees the same size as Fahren- 

 heit's degrees, then 0° F. is 459.4 absolute; 50° F. is 459.4 + 50 = 509.4 absolute, etc. 



