’Tis observable, that people are rous’d out of a fit of the Night-mare, sometimes, by sound alone. I remember to have been under it, when a Servant came in the morning to make a fire, and let the coal-box fall at the door; the noise of which effectually reliev’d me. The vibrations or undulations of the air beating upon the drum of the Ear, may act as a successful stimulus in this case. As this Disease seems to arise immediately from a supine position of the Body in sleep, we should take care to prevent it before we fall asleep, by composing the Body on either Side. The sagacious Hoffman observes, that the safest posture in sleep, is on either Side, with the Head rais’d, and the Limbs bent inwards to the trunk of the Body[43]. Some ingenious men have imagin’d, that the bending of the Limbs in sleep is owing to the strong tendency which the flexor Muscles have to contraction; but I humbly suppose, it is rather a voluntary motion, intended to fix the Body on the Side, without the continued action of any of the voluntary Muscles afterwards; for without the flexion of the Joints in sleep, it would be a kind of labour to keep the Body pois’d on such an narrow surface. To demonstrate this, I shall avoid mathematics, and appeal to common sense, for an easy experiment. Suppose one should endeavour to poise a thin plate of tin on its edge upon a smooth, level table; if he be not an expert equilibrist, he will find it difficult; but if he bends the plate, then the problem becomes as easy as the well known method of making an egg stand on its end. This easy method, which nature has contriv’d to preserve the human Body on its side, is a sufficient recommendation of that position, and a strong precaution against lying on the Back, which is the posture of dead Bodies. Before any regular or effectual plan of curing, or rather preventing, this Disease, can be propos’d, it will be always necessary to consider minutely the primary or pre-disposing causes of it, formerly mention’d. If the primary cause be a weakness of the Fibres, then strengthening or astringent medicines are proper; which, by increasing the cohesion of the constituent particles of the Solids, will make the Fibres more dense, brace them up to a proper pitch, and quicken their vibrations. The principal Medicines of this class are iron, and its preparations, the Bark, the wild Valerian-root, and the cold Bath. If it arises from an inertia or indolence of the Solids, nervous medicines will best answer that indication; which, by stimulating the lazy inactive Fibres, will increase their elasticity, invigorate their contractions, accelerate the motion, and break the tenacity of the Blood. If the Blood be too thick, attenuants should be us’d, such as, spiritus Mendereri[44], vegetable subacid liquors, saponaceous medicines, and plenty of vinegar at meals, which, according to the great Boerhaave, is a powerful diluent[45].