Poisoning by mussels is much more frequent than by oysters. At Wilhelmshaven,[234] in Germany, in 1885, large numbers of persons were poisoned, and some died, from eating mussels taken from the harbour. It was found that when transferred to open water these mussels became innocuous, while, on the other hand, mussels from outside, placed in the harbour, became poisonous. The cause obviously lay in the stagnant and corrupted waters of the harbour, which were rarely freshened by tides. It was proved to demonstration that the poison was not due to decomposition; the liver of the mussels was the poisonous part. In the persons affected, the symptoms were of three kinds, exanthematous (skin eruptions), choleraic, and paralytic. Cases of similar poisoning are not unfrequent in our own country, and the circumstances tend to show that, besides the danger from mussels bred in stagnant water, there is also risk in eating them when ‘out of season’ in the spawning time. _Whelks_ are very largely employed for bait, especially in the cod fishery. The whelk fishery in Whitstable Bay, both for bait and for human food, yields £12,000 a year. Dr. Johnston, of Berwick, estimated that about 12 million limpets were annually consumed for bait in that district alone. The cockle fishery in Carmarthen Bay employs from 500 to 600 families, and is worth £15,000 a year, that in Morecambe Bay is worth £20,000. =Cultivation of Snails for Food; Use as Medicine.=--It was a certain Fulvius Hirpinus who, according to Pliny the elder,[235] first instituted snail preserves at Tarquinium, about 50 B.C. He appears to have bred several species in his ‘cochlearia,’ keeping them separate from one another. In one division were the _albulae_, which came from Reate; in another the ‘very big snails’ (probably _H. lucorum_), from Illyria; in a third the African snails, whose characteristic was their fecundity; in a fourth those from Soletum, noted for their ‘nobility.’ To increase the size of his snails, Hirpinus fed them on a fattening mixture of meal and new wine, and, says the author in a burst of enthusiasm, ‘the glory of this art was carried to such an extent that a single snail-shell was capable of holding eighty sixpenny pieces.’ Varro[236] recommends that the snaileries be surrounded by a ditch, to save the expense of a special slave to catch the runaways. Snails were not regarded by the Romans as a particular luxury. Pliny the younger reproaches[237] his friend Septicius Clarus for breaking a dinner engagement with him, at which the _menu_ was to have been a lettuce, three snails and two eggs apiece, barley water, mead and snow, olives, beetroot, gourds and truffles, and going off somewhere else where he got oysters, scallops, and sea-urchins. In Horace’s time they were used as a gentle stimulant to the appetite, for “’Tis best with roasted shrimps and Afric snails To rouse your drinker when his vigour fails.”[238]