(From mollis, soft). Natural history has, within these few years, greatly extended its boundaries by new discoveries. Philosophers wanted new worlds as a supply for their ambition, new territories for their conquest, and they have discovered them by improving their instruments, by their more extensive and more acute observation. New planets,new metals, and new animals are daily attracting our attention, and, in the present department of science, they have neglected the gaudy shell, the former object of inquiry, and the subject of classification, to ascertain the nature of the animal which inhabits it. This part of the inquiry has been chiefly cultivated by the French naturalists, and the reader will obtain the most satisfactory information from these and the Linnaean Transactions. We must add, however, with regret, that the volumes, which relate to the mollusca by the successor of Denys Montfort, are inferior to many of the others, and the plan of that naturalist is not completed. In this place we can only skim over the surface, in order to apply it to medicine. We have already noticed the great outline drawn by La Marck and Cuvier, who divide animals into those which have articulated vertebrae, and those which want them. We say articulated vertebrae, because some of the animals before us have a bony support, particularly the cuttle fish. When vertebrae are no longer found, the blood isno longer red. All these animals were divided into insects and worms, or, as they are now called, molluscae; but later authors have added and detracted a little from the classes of their predecessors. Bruguicre added the echinodermes, viz. the star fish and the urchins. La Marck reduced the six classes of Bruguiere to four, molluscae, worms, radiarii (echinodermes) and the polypi, including the infusory animals. Denys Montfort, whose work, as the chief systematic one, we must follow, divides the molluscae into ten classes, the M. coriaceae (cuttlefish); tentaculatae (snails); ejaculatores (many of the bivalves); annulatae (worms); gelatinosae (medusas or blubbers); loricate (asterias); hydra (multivalves); polypi (madrepores); cornea (lithophy-tes); infusoria (microscopic animals). In this arrangement, the insects, the crustaceae, and arachnoides, are excluded; for the molluscae undergo no metamorphosis, do not change their skins, and have no really articulated limbs.

The coriaceae once furnished their shells as absorbent medicines. They sunk into dentrifices, and are now disregarded. One species, the sepia octopus, the octopus vulgaris of La Marck is said by AEtius, and many of the other Greek physicians, as well as the poets, to be aphrodisiac. The sepia moschata (octopus moschatus of La Marck) was esteemed for the same qualities,aiso as an emmenagogue, and as highly nutrient. All the polypi are occasionally eaten. They are a hard indigestible food, employed only from necessity, and rendered as palatable as possible by the arts of cookery. The tongue is said to be delicious, and is greedily devoured raw. The animal styled the argonaut is of this genus; and the nautili which agree in structure with it, though not like the former, are solitary animals, also eaten by the common people.

With these animals the work of Denys Montfort concludes, and his successor is peculiarly short, imperfect, and unsatisfactory. The tentaculatae furnish animals highly nutritive, and employed on this account in hectics. The gluten of the large black snail is said to be useful as a discutient. The only other divisions which offer medicinal substances is the seventh, which contains the sponge, and the ninth, the lithophytes, which furnish the coralline.

Histoire Naturelle de Buffon Ed. Sonnini. Molusca. Memoires et lhistoire de la Societe dhistoire Natu-relle, a Paris, Annales du Musaeum National. Linnaean Transactions.