vitality, for if the respiration be only suspended for a short interval, we may conclude that life has fled for ever; of all the acts of animal life this is by far the most essential and indispensable; _breath_ and _life_ are very properly considered in the scriptures as convertible terms, and the same synonym, as far as we know, prevails in every language.[9] However slow and feeble respiration may become by disease, yet it must always be perceptible, provided the naked breast and belly be exposed; for when the intercostal muscles act, the ribs are elevated, and the sternum is pushed forward; when the diaphragm acts, the abdomen swells; now this can never escape the attentive eye, and by looking at the chest and belly we shall form a safer conclusion than by the popular methods which have been usually adopted, such as the placing a vessel of water on the thorax, in order to judge by the stillness or agitation of the fluid; or holding the surface of a mirror before the mouth, which, by condensing the aqueous vapour of the breath, is supposed to denote the existence of respiration, although too feeble to be recognised in any other way. ----“Lend me a looking-glass; If that her breath will mist or stain the stone, Why, then she lives.” _Lear_, _Act_ v, _s._ iii. For the same purpose, light down, or any flocculent substance, from the extreme facility with which it is moved, has been supposed capable of furnishing a similar indication; but the result must not be received as an unequivocal proof, and accordingly _Shakspeare_, with that knowledge and judgment which so pre-eminently distinguish him, has represented _Prince Henry_ as having been thus deluded, when he carried off the crown from the pillow of _Henry_ the _Fourth_— --------------“By his gates of breath There lies a downy feather, which stirs not. Did he suspire, that light and weightless down Perchance must move.” With respect to the above tests it may be remarked, that an imperceptible current of air may agitate the light down, and thus simulate the effects of respiration, while an exhalation, totally unconnected with that function, may sully the surface of a mirror held before the mouth; on the other hand, we have learnt from experience that mirrors have been applied to persons in a state of mere syncope without being in the least tarnished.