STATISTICAL AND OTHER INFORMATION. 891 



under the most favourable conditions, is none too long, 

 but it is in a measure dependent upon controllable causes, 

 and these are worthy of careful consideration. 



To extend this period to the utmost limit, it is of the 

 very greatest importance that the preserving influence 

 begins as soon as the fish are out of the water, and 

 before deterioration sets in ; in other words, the animal 

 or natural heat should be withdrawn, and the fish cooled 

 from surface to centre as quickly as possible. This 

 speedy cooling necessitates not only a low temperature, 

 but room for spreading the fish, or appliances for separat- 

 ing them into layers, so as to allow free circulation of the 

 cooled air. Absolute cleanliness in every department is of 

 vital importance. You may as well lodge a perfectly 

 healthy person in the bed of a small-pox patient, as to 

 pack freshly-caught fish in boxes or compartments con- 

 taminated with the filth and slime of previous putrefaction. 

 If any fisherman entertains a doubt upon this point, let 

 him place a row of fish side by side, backs upwards, upon 

 a filthy board in the bottom of his boat, and he will find 

 that the bellies of these fish are completely rotten when 

 the sides and back are apparently sound. 



. . . . Packing fish in ice may be fairly considered 

 as a choice of evils. Some fish, salmon for instance, 



These results by Schwann were confirmed by the experiments of 

 Helmholtz in 1843, by Schroder and Von Dusch in 1854, by Schroder 

 alone again in 1857, by Pasteur in 1862, and by Tyndall in 1868-9. 



In 1872 Cohn of Breslau announced that "putrefaction begins as 

 soon as Bacteria, even in the smallest numbers, are introduced. It 

 progresses in direct proportion to the multiplication of Bacteria. It is 

 retarded when the Bacteria (for example by a low temperature) develop 

 a small amount of vitality, and is brought to an end by all influences 

 which either stop the development of Bacteria or kill them." " Fish 

 Preservation and Refrigeration," pp. 1-3. 



