SLEEP. 599 



the easiest position in our power, that which approaches the 

 nearest to the horizontal, so that we may have to make no mus- 

 cular effort; we gape, and yawn ; a degree of delirium b is ex- 

 perienced, from the impaired condition, short of suppression, of 

 our feeling and attention. This delirium or wandering when we 

 are between sleeping and waking is a much surer sign that we 

 are about to get to sleep than the consciousness of the greatest 

 drowsiness. A heaviness of the upper eyelid ; smarting of the 

 eyes, such as to give rise to the common remark to a sleepy 

 person, that the dustman has thrown dust into them ; peevish- 

 ness, especially in children ; chilliness ; also precede sleep that 

 does not come on suddenly. The breathing grows slower in 

 two respects, as to the intervals of the respirations and as to in- 

 spiration, and on this very account it becomes deeper, and takes 

 place with increased sound : and in adults snoring is a common 

 occurrence during sleep, and takes place if the inspirations are 

 forcible, and if circumstances favour an open state of the 

 mouth, so that the velum palati, being relaxed, is thrown into 

 vibrations by the passing air, or if more or less of the tongue 

 lies up against the palate, so that the nose is made to vi- 

 brate ; and if the mouth is closed, palatal snoring will still occur 

 should a portion of the tongue touch the palate, and snoring will 

 be more and more nasal the greater this portion of the tongue* 

 Like the respiration, the pulse grows slower and fuller. To ex- 

 clude the light as much as possible, the pupil becomes contracted, 

 and the eyes sometimes turn up or down. The temperature falls 

 somewhat. The transpiration is found to increase ; and, when 

 persons are weak, this is shown by its occurring frequently to the 

 amount of sweating as soon as ever they fall asleep. From 

 this circumstance, and the cessation of drinking, less urine is se- 

 creted; and, from the motionless state of the lower jaws and tongue, 

 and the absence of food from the mouth, there is less saliva and 

 oral mucus ; from the absence of light and the quiet state of 

 the eyes and eyelids, less lachrymal secretion. But, except from 

 such absence of stimuli which act in the waking state, I doubt 

 whether secretion is lessened in sleep : that it is not necessarily 

 lessened, is shown by the increase of perspiration. Dr. Macnish 



b " De Pauw has some singular/ bservations upon it in his Recherches sur les 

 Egyptiens et les Chinois, t. ii. p. 1' J." 



