156 FISH CULTURE 



tures there is more rapid breathing and there- 

 fore a greater amount of oxygen consumed. 



Salt-Baths. — ^Mention has been made of the 

 use of salt. It is both important and necessary 

 in successful trout work. Salt is to the fish- 

 culturist "what calomel or quinine is to the doc- 

 tor of human patients, a sort of preliminary 

 cure-all. On the other hand it should also be 

 said, by way of caution, that salt is to a fish what 

 strychnine is to mankind — death, when admin- 

 istered in too heavy doses, a powerful stimulant 

 when used under proper conditions and in due 

 proportions. Salt is also useful as a cleanser 

 of troughs and ponds. The discovery of the 

 valuable medical and hygienic qualities of salt 

 in fish-cultural work was made in 1872 by Liv- 

 ingston Stone. 



Salt baths for fry are advisable, as they act 

 as preventives of gill troubles. They should 

 be administered in varying degrees of strength 

 regulated by needs of the different stages of 

 disease that may present themselves. In very 

 mild cases, or when there is slight indication of 

 sickness among the fry, the salt can be placed 

 at the head of a trough where the water from 



