890 OYSTERS, AND ALL ABOUT THEM. 



that freezing completely checks all putrefactive action, and 

 when in this frozen condition meat or fish can be kept for 

 an indefinite length of time. A noticeable instance of this 

 was seen in the salmon brought from Labrador, in the ss. 

 Diana, in 1881. A part of this cargo was taken from 

 London to Australia, and after this long voyage across the 

 tropics, and 200 days out of water, these salmon were 

 found to be in good condition. 



. . . . The advantages to be derived from this 

 method of preservation (freezing) have not been, nor are 

 they now, fully appreciated ; public opinion seems to have 

 settled quietly into the belief of the oft-repeated statement 

 that it " destroys the flavour of fish to freeze them," and 

 that "they go bad so quick after they are restored to 

 normal temperature." Neither of these statements is 

 well founded, although they may be in accord with the 

 observations of those who make them. 



The flavour of a fish and its keeping quality after 

 thawing, depend more upon its condition when frozen than 

 upon the deleterious action of the low temperature in which 

 it has been kept. It should be constantly borne in mind that 

 there is no restorative power in any system of preservation. 



Inasmuch as a temperature above freezing 

 does not completely check, but only retards, bacterial 

 development, (/) it follows that the preserving effect can 

 only be for a limited period. The duration of this period, 



(/) Scbwann, of Berlin, was the first to prove that living germs are 

 the cause of putrefaction, and in 1837 he made the important announce- 

 ment that when a decoction of meat is effectually screened from ordi- 

 nary air, and supplied solely with calcined air, putrefaction never sets 

 in. Putrefaction, therefore, he affirmed to be caused not by the air, 

 but by something in the air which could be destroyed by a sufficiently 

 high temperature. 



