56 



til re, the original character or quality of the water, the 

 size and character of the lish (some sj)ecies requiring more 

 oxygen than others, and large lish needing more than small 

 ones), and many other variable influences, tend to make the 

 consideration of such a method a very complex problem. 



A series of experiments conducted for the purpose of de- 

 termining the value of such a system would have to be 

 very comprehensive indeed. Numbers of expensive chemi- 

 cal analyses would have to be made, and the comparisons 

 would have to be very careful, all involving a long period 

 of experiment and observation. The researches through 

 which our knowledge of the diffusion of gases in the at- 

 mosphere have been derived have occupied the minds of 

 eminent physicists through long periods of time, devoted 

 to patient and la])orious experiment. 



It is probable, however, that for all practical purposes 

 the question can be discussed and its practicability deter- 

 mined by examination from a purely theoretical stand- 

 point. 



It is an undoubted fact that flsh may be kept in hermeti- 

 cally sealed vessels for a considerable time without the 

 action of plant-life or artificial aeration. The possibilities 

 in this direction increase with decrease in the temperature, 

 the number and size of the tish, and with flsh requiring a 

 smaller amount of oxygen. When a certain proportion of 

 oxygen is exhausted of course the flsh must die. As to 

 whether the idea can ever have a positive practical value, 

 however, is at least very doubtful. 



In the flrst place, any apparatus developed in accord- 

 ance with such a system, and adapted to purposes of dis- 

 tribution, would tend towards complexity in construction 

 and manipulation, whereas simplicity is the great desid- 

 eratum. 



The advantage that would apparently arise from the 

 adoption of hermetically sealed vessels is that as air is 

 absorbed and held in suspension in water, or expelled 



