ON ARTIFICIAL REFRIGERATION. 065 



than profit. Cold houses, for tlie temporary preservation of fish, are, 

 th'jrel'ore, even lor tliese purposes, invahiable. 



It is not my object to dilate on those used for the process ot freezing^ 

 as adopted by some of the more enterprising dealers in fish. If, as I 

 have before said, it be found best to freeze fish under certain circum- 

 stances, the most economical plan admits of very ready descrii)tion. 



Mr. Frank lUickland informed me some years since that he had re- 

 ceived in London, from Glasgow, a mass offish frozen in a block of ice; 

 that they looked Avell, but could jiot be separated for the trade without 

 thawing- the ice. This experiment, often repeated, indicates how effect- 

 ually not only one but many fish may be frozen en mame. It may be in- 

 cidentally remarked that certain kinds of hardy fresh- water fish may be 

 frozen alive in a block of ice, and kept there for a time not yet well de- 

 fined, but extending, at all events, over many days or weeks, and on 

 thawing the ice the fish prove to have been unharmed. What tem])era- 

 ture they mil withstand is not known, and, in relation to fish-culture, 

 this is another field for inquiry of the highest interest. It is just pos- 

 sible that some fish may be transported frozen to stock rivers or seas 

 more easily than they can be carried in a water-tank, and whether a sole 

 or turbot will resist such usage I cannot say ; the experiments have 

 yet to be made ; and aU we know is that some fish, like pike, may sur- 

 vive the process. It would not be difficult to try the experiment, inas- 

 much as a flat metal can containing the fish could be very rapidly frozen 

 by a surrounding solution of glycerine and water from a fi'eezing-ma- 

 chine, and, by selecting the proper cryogen, a temperature not much 

 below 32° Fahr. might be readily maintained in a tub, containing the said 

 metal can, on its passage across the Atlantic. The information at my 

 disposal is so scanty that, apart from the fact that fish have sm-vived 

 freezing in a solid block of ice, I know nothing. It occurs to me, how- 

 ever, that in all probability the temperature of 32^ Fahr. is low enough 

 for most fishes, and the obvious use of common salt and ice might be 

 attended by too low a temperature to insure success. Many failures 

 may be anticipated ; but without these, good work was rarely performed. 



The present practice of freezing each individual fish solid and then 

 keeping a quantity on hand from seasons of plenty to those of scarcity, 

 is, of coiu'se, more feasible because less costly by the use of an ice-ma- 

 chine than by ice and salt. The uncongealable liquid would take the 

 place of the brine, and very little, if any, alteration in plant, beyond the 

 addition of a machine, would probably be requu^ed. The sooner the fish 

 are frozen after being caught the better, and they must not be allowed 

 to thaw until the time for cooking them. Frozen fish are packed in fine 

 sawdust and closely boxed to be sent two or three hundred miles, thaw- 

 ing out slowly in transit ; they are then dropped in water to complete 

 the thawing, and are ready to cook. 



Professor Goode informs me that " the total amount of iced halibut 

 brought annually to the port of Gloucester is not far from 10,000,000 



