Radcliffe. — Fishery Products Laboratories 9 



product will be "case hardened" and slower drying will result 

 than if the air at first were moist and cooler, the humidity being 

 lowered and the temperature raised as drying progresses. Unless 

 all these influencing factors are known and measured, it will be 

 impossible to judge what can be expected from efforts to dry fish 

 under circumstances different from those under which the experi- 

 ments were conducted. With all these factors under exact 

 and measurable control, the reproduction of the air conditions 

 which prevail in any part of the country and the experimental 

 drying of fishes under these conditions is a possibility. Remarkable 

 progress is being made in the dehydration of vegetables. Until 

 the subject has been investigated, who is able to forsee the possi- 

 bilities of dehydration and dessication of fishery products? 



The practice of preserving fish by smoking is very ancient and 

 the products properly prepared may be numbered among the 

 tastiest of foods. Yet how little attention has been given to the 

 finesse of their preparation by trained technologists, how much 

 of that offered for sale is only mediocre in quality. The varying 

 composition of smoke from different fuels and at different tem- 

 peratures, the penetration of the smoke, the subsequent fractional 

 evaporation of the deposited smoke constituents from the fish, the 

 possible addition of flavoring oils to the fuel, the coloring of the 

 product, the prevention of mold on the smoked fish, possibilities 

 of other improvements in keeping qualities and in technique of 

 preparation, all should be given careful study. 



The preservation of fish by means of dry salt, of pickles 

 including brine, vinegar, etc., with or without the addition of 

 spices and the prevention of spoilage of the prepared products, 

 present a wide variety of problems, the solution of which would 

 be of the greatest value to the industry. There has been need for 

 information as to the relative values of the different grades of salt, 

 of the advantages or disadvantages of the dry salting method as 

 compared with brine salting, etc. Considerable losses are sus- 

 tained due to the reddening of dry salted fish and the "souring" 

 of the pickle in brine salted fish. The salability of fish is hurt 

 by rust and production is curtailed on account of our inability to 

 salt fish at high temperatures and therefore in warm climates. 



Although the process of preserving foods by canning is more 

 than a hundred years old, it is only within the last decade that this 



