Night-Mare, or Incubus, a singular affection, occasioned by a spasmodic state either of the lungs or the abdomen ; by a redundancy of blood, or a partial stagnation, in its passage through the heart and the pulmonary vessels.

During this affection, the patient perceives, or imagines that he feels, an uncommon oppression in the region of the breast and stomach, which no effort can remove. Sometimes he groans, and screams, but more frequently in vain endeavours to speak. At other times, he fancies himself struggling with an enemy, or with demons ; to be in a house that is in flames ; or in danger of being drowned, etc. so that the terror induced by the frightful ideas which accompany these uneasy sensations, causes a tingling in the ears, and produces a general tremor.

The night-mare chiefly attacks nervous, hypochondriac, or delicate persons, when lying on their back: beside the causes above stated, it may, in many instances, be assigned to indigestion. Hence persons of sedentary habits and weak nerves, especially those who are subject to flatulency, ought carefully to avoid all coarse and heavy nutrimen ; to eat light but nourishing food; to abstain from late, or solid suppers; and lastly, to raise their heads in bed tolerably high. As those who are attacked with the night-mare generally groan when labouring under a fit, it will be requisite to address or wake them instantly, as the uneasiness will thus be greatly removed. Should, however, the paroxysm continue to increase, it will be useful to administer small, but frequent doses of valerian, asa-foetida, or other anti-spasmodics, and to strengthen the body with the mildest chalybeates. But if young persons of plethoric habits be subject to this affection, it will be advisable to use a spare diet, to take daily exercise in the open air, and to attend to the state of the bowels, in order to prevent costiveness.