INTEODUCTOEY. 5 



Subsequently to this, but more than a century ago, 

 we find another discoverer who appears to have prac- 

 tised the artificial hatching of fish, and in a very 

 complete and simple manner. This was Lieutenant 

 Jacobi, a German gentleman. His mode of proceed- 

 ing is detailed in a series of papers published in the 

 Hanover Magazine, in 1763—4 and 5. This gentle- 

 man appears to have experimented upon various 

 kinds of fresh-water fish, and to have been suc- 

 cessful with all of them. The plan he adopted for 

 hatching salmon and trout was to construct a long 

 oaken box, with fine gratings at the top and ends ; 

 to fill it partially with gravel, and, having pro- 

 cured the ripe spawn from a female fish, and fecun- 

 dated it by mixing it with the milt of the male, to 

 deposit it in the gravel in the box ; and having then 

 placed the box in a clear running stream of a suitable 

 depth, he left the task of incubation to nature. Sir 

 Humphrey Davy, in his " Salmonia," gives a full 

 account of Jacobi's plan and proceedings. And 

 this plan, with little alteration, is in use at the 

 present day. But the art, from some cause, for a 

 long series of years, fell into disuse, and was well- 

 nigh forgotten, when Mr. Shaw, of Drumlanrig, beibg 

 anxious to decide the "parr question," carried out 

 a series of experiments, which extended over many 



