recovered and was as strong and lively as the rest of the litter. After allowing the other two about an hour to breathe, I put them once more into the warm milk, in which they remained another half hour. Whether they swallowed any of this liquor or not is uncertain; but on being taken out they appeared nearly as vigorous as ever. After being carried to the mother, however, one died the same day; but whether by any accident, or by what it had suffered while immersed in the liquid, and deprived of air, I could not determine. The other lived, as well as the first, and both throve equally with those which had not gone through the same trials. This experiment I never carried farther; but I saw enough to convince me that respiration is less necessary to a new-born, than to a grown animal; and that it might be possible, with proper precautions, to keep the foramen ovale from being closed, and thus produce excellent divers, and different kinds of amphibious animals, which might live equally in air or in water. The air, on its first admission into the lungs, generally meets with some obstacle, occasioned by a liquid collected in the wind-pipe. This obstacle is more or less great, in proportion as the liquid is more or less viscous. At its birth, however, the infant raises its head, which before reclined on its breast, and by this movement the canal of the wind-pipe is lengthened, the air obtains a place, and forces the liquid into the lungs: and by dilating the bronchia, it distributes over their coats the mucous substance which opposes its passage. The superfluity of this moisture is presently dried up by the renewal of the air; or, if the infant is incommoded by it, it coughs, and at length relieves itself by expectoration, which, as it has not yet the strength to spit, is seen to flow from the mouth. As we remember nothing of what happened to us at this period, it is impossible to determine what feelings the impression of air produces in a new-born infant. Its cries, however, the instant it first draws breath, are pretty certain signs of the pain it feels from the action of the air. Till the moment of its birth, the infant is accustomed to the mild warmth of a tranquil liquid; and we may suppose, that the action of a fluid, whose temperature is unequal, gives too violent a shock to the delicate fibres of its body. By warmth and by cold it seems to be equally affected; in every situation it complains, and pain appears to be its first, its only sensation.