Cuutivate Exrrs anp Froas. 358 
sands of ecls are thus annually gathered and cured for mar- 
ket, because there is a greater number of fresh eels than is 
necessary to supply the markets of Italy. 
At the commencement of the decade of the eighteenth cen- 
tury the brilliant discoveries of Spallanzani enriched the nat- 
ural sciences, and proved beyond reasonable doubt the possi- 
bility of developing the mysteries which theorists had from 
time to time mooted, of impregnating the eggs of fishes arti- 
ficially. He therefore took eges of a frog, and impregnated 
them with the semen ofa male frog. This he did before nu- 
merous Witnesses, who saw the live frogs, and saw that from 
these eggs young frogs were hatched, and the triumph of the 
illustrious Italian naturalist was thus rendered complete. 
In 1763 Lieut. Jacobi announced through a journal of Han- 
over the feasibility of the artificial fecundation of salmon 
and trout. Before, however, publishing his successful exper- 
iments, he endeavored to promulgate his discovery through 
the medium of celebrated naturalists, such as Buffon, De Four- 
croy, and Gleditch, an eminent professor of Germany. “ Les 
savants” of France appeared too much preoccupied to notice 
the Hanoverian lieutenant, especially as his writings were in 
German. Gleditch, who was not influenced by the same rea- 
sons, appeared impressed with the work of Jacobi, and he com- 
municated extracts from the work to the Academy of Berlin 
through Baron Von Harbke. 
In France the experiences relative to the artificial feeunda- 
tion of fishes occurred some years later. The work of Jacobi 
was published in Paris in 1770. The Marguis de Pezay, in 
his Sotrées helvétiennes, signalized the fortunate results ob- 
tained at Noterlem, including the information that England 
wished to recompense Jacobi by a liberal pension. 
Two years thereafter, and twelve years after the successful 
experiments of Jacobi, Adamson, in his course at the Jardin 
du Roi in 1772, made known to his auditors the plan and 
practicability of artificial fecundation, stating that it was ha- 
bitually practiced on the borders of the Weser, in Switzer- 
Z 
