74 JACOBI'S EXPERIMENTS. [CHAP. in. 



of such discoveries, and till a discovery be turned to some 

 practical use, it is, in a sense, no discovery at all. After 

 being lost for many hundred years, the art of artificially 

 spawning fish was re-discovered in Germany by one Jacobi, 

 and practised on some trout more than a century ago. This 

 gentleman not only practised pisciculture himself, but wrote 

 essays on the subject as well. His elaborate treatise on 

 the art of fish-culture was written in the German language, 

 but also translated into Latin, and inserted by Duhamel du 

 Monceau, in his General Treatise on Fishes. Jacobi, who 

 practised the art for thirty years, was not satisfied with a 

 mere discovery, but at once turned what he had discovered to 

 practical account, and, in the time of Jacobi, great attention 

 was devoted to pisciculture by various gentlemen of scientific 

 eminence. Count Goldstein, a savan of the period, likewise 

 wrote on the subject. The Journal of Hanover also had 

 papers on this art, and an account of Jacobi's proceedings was 

 enrolled in the Memoirs of the Eoyal Academy of Berlin. 

 This discovery of Jacobi was the simple result of keen 

 observation of the natural action of the breeding salmon. 

 Observing that the process of impregnation was entirely an 

 external act, he saw at once that this could be easily imitated 

 by careful manipulation ; so that, by conducting artificial 

 hatching on a large scale, a constant and unfailing supply of 

 fish might readily be obtained. The results arrived at by 

 Jacobi were of vast importance, and obtained not only the 

 recognition of his government, but also the more solid reward 

 of a pension. I need not detail the experiments of Jacobi, as 

 they are very similar to those of others that I intend to de- 

 scribe at full length in this portion of my narrative. 



Some persons dispute the claims of France to the honour 

 of this discovery, asserting that the peasant Eemy had bor- 

 rowed his idea from the experiments of Shaw of Drumlanrig, 

 who had by the artificial system undertaken to prove that parrs 



