ON ACEPHALA. 379 
and salt water; to the influence of the solar action, of the 
north-east wind, of a moderate temperature, but by no means 
to any single immediate cause. They are not at all disposed 
to coincide with the theory of M. Gaillon, above mentioned, 
against which they have many objections; but it would be 
too long to enumerate them. 
The transportation of the oysters, thus become marketable, 
still demands some precautions. ‘They must always be placed 
in their natural position, that is to say, horizontally, the 
hollow valve underneath, so that they may lose less of the 
water which bathes their gills. It is equally advantageous 
that they should be enveloped in fucus, or marine plants, to 
avoid the drying action of the air. The quicker this trans- 
portation takes place the better, especially when the weather 
is a little warm. But as this mode by land is very expensive, 
during the winter oysters are brought to Paris in rather large 
boats, which come from St. Vast, by the Somme. Then they 
are very cheap at Paris. Some years back, a notion was en- 
tertained of no longer sending oysters dry, but in a boat full 
of sea-water, after the manner of the Romans. But the at- 
tempt did not succeed, for so small a quantity of water, con- 
taining so many animals, not being capable of being renewed, 
soon putrified, as sea-water easily does, and caused the death 
of so great a number of oysters, that the police were forced 
to order the whole to be thrown into the river. 
Oysters of good quality, are in general easy of digestion, 
but not very nutritious, especially when they are eaten raw. 
They rather act as a provocative to appetite, which is occa- 
sioned by the agreeably subsaline water which they contain. 
Persons have been known to eat fifteen or twenty dozen at a 
meal, without experiencing any inconvenience. It would not 
have been the same if they had been cooked; they then be- 
come harder, more coriaceous, and consequently more indi- 
gestible. They are also eaten pickled with vinegar and fine 
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