s supposed to be produced from a kind of consent or sympathy between several parts of the body, occasioned by the same nerve being extended to them all. Thus the fifth pair of nerves being branched from the brain to the eye, ear, muscles of the lips, cheeks, palate, tongue, and nose; a thing seen or heard that is shameful, affects the cheeks with blushes, driving the blood into the minute vessels thereof, at the same time that it affects the eye and ear. For the same reason it is, as Mr Derham observes, that a savoury thing seen or smelled affects the glands and parts of the mouth: if a thing heard be pleasing, it affects the muscles of the face with laughter; if melancholy, it exerts itself on the glands of the eyes, and occasions weeping, &c. And to the same cause Dr Willis attributes the pleasure of kissing.

**Boa,** or Boae-arwn, (anc. geog.), an island on the coast of Illyricum, over against Tragurium. A place of banishment for condemned persons; now called Bua, an island in the Adriatic, joined to the continent and to Tragurium, now Trau, by a bridge.

**Boa,** in zoology, a genus of serpents, belonging to the order of amphibia. The characters of this genus are, that the belly and tail are both furnished with scuta. The species are ten, viz. 1. The contortrix, has 150 scuta on the belly, and 40 on the tail; the head is broad, very convex, and has poison-bags in the mouth, but no fang, for which reason its bite is not reckoned poisonous; the body is ash-coloured, intermixed with large dusky spots; and the tail is about a third of the length of the body. This serpent is found in Carolina.

2. The canina, has 203 scuta on the belly, and 77 on the tail; it is greenish, and variegated with white belts. It is a native of America, and lodges in the hollow trunks of trees, and is about two feet long. The bite of the canina is not poisonous.

3. The hipnale is of a dull yellow colour, and is found in Asia. It has 179 scuta on the belly, and 120 on the tail.

4. The constrictor, has 240 scuta on the belly, and 60 on the tail. This is an immense animal; it often exceeds 56 feet in length; the body is very thick, of a dusky white colour, and its back is intermixed with 24 large pale irregular spots; the tail is of a darker colour; and the sides are beautifully variegated with pale spots. Besides, the whole body is intermixed with small brown spots. The head is covered with small scales, and has no broad lamina between the eyes, but has a black belt behind the eyes. It wants the large dog-fangs, and of course its bite is not poisonous. The tongue is fleshy, and very little forked. Above the eyes, on each side, the head rises high. The scales of this serpent are all very small, roundish, and smooth. The tail does not exceed one eighth of the whole length of the animal. The Indians, who adore this monstrous animal, use the skin for cloaths, on account of its smoothness and beauty. There are several of these skins of the above dimensions preserved, and to be seen in the different museums of Europe, particularly in the library and botanic garden of Upsal in Sweden, which has of late been greatly enriched by count Grillinborg.

The flesh of this serpent is eaten by the Indians and the negroes of Africa. Pifo, Margraave, and Kempfer, give the following account of its method of living and catching its prey. It frequents caves and thick forests, where it conceals itself, and suddenly darts out upon strangers, wild beasts, &c. When it chooses a tree for its watching place, it supports itself by twisting its tail round the trunk or a branch, and darts down upon sheep, goats, tigers, or any animal that comes within its reach. When it lays hold of animals, especially any of the larger kinds, it twirls itself several times round their body, and by the vast force of its circular muscles bruises and breaks all their bones. After the bones are broke, it licks the skin of the animal all over, befoaming it with a glutinous kind of saliva. This operation is intended to facilitate deglutition, and is a preparation for swallowing the whole animal. If it be a stag, or any horned animal, it begins to swallow the feet first, and gradually sucks in the body, and last of all the head. When the horns happen to be large, this serpent has been observed to go about for a long time with the horns of a stag sticking out from its mouth. As the animal digests, the horns putrefy and fall off. After this serpent has swallowed a stag or a tiger, it is unable for some days to move; the hunters, who are well acquainted with this circumstance, always take this opportunity of destroying it. When irritated, it makes a loud hissing noise. This serpent is said to cover itself over with leaves in such places as stags or other animals frequent, in order to conceal itself from their sight, and that it may the more easily lay hold of them.

5. The murina, has 254 scuta on the belly, and 65 on the tail. The colour of it is a light blue, with round spots on the back. It is a native of America, and its bite is not poisonous.

6. The scytale, has 250 scuta on the belly, and 70 on the tail. The body is ash-coloured and bluish, with round black spots on the back, and black lateral rings edged with white. This serpent is a native of America; and, like the constrictor, though not so long, twists itself about sheep, goats, &c. and swallows them whole.

7. The cenchria, has 265 scuta on the belly, and 57 on the tail. It is of a yellow colour, with white eye-like spots. It is a native of Surinam, and its bite is not poisonous.

8. The ophiata, has 281 scuta on the belly, and 64 on the tail; the colour is nearly the same with that of the constrictor, but browner. The place where this serpent is to be found is not known; but its bite is not venomous.

9. The enydra, has 270 scuta on the belly, and 105 on the tail. The colour is a dusky white, and the teeth of the lower jaw are very long; but its bite is not poisonous. It is a native of America.

10. The hortulana, has 290 scuta on the belly, and 128 on the tail. It is of a pale colour, intermixed with vivid wedge-like spots. It is a native of America, and its bite is not poisonous.

See Serpent.