Coma is the medical word for this. It is an unnaturally deep sleep, from which one cannot be roused. We meet with it chiefly in the following : Alcoholic drunkenness ('dead drunk"); opium-poisoning (narcotism) ; apoplexy ; very low typhus fever ; compression of the brain from fractured skull.

It is not always easy to say, in a particular case, which of these is present.

Intoxication is generally shown by the odor of the breath, and the general appearance of the patient, and his behavior before he became unconscious. In opium poisoning, the pupils of the eyes are, as a rule, strongly-contracted, even when no considerable light is shining on them. Typhus fever is known by the history of the case ; as, in it, complete stupor is never the condition at the very beginning of the illness. A broken skull, if not obviously accounted for by a known injury, may be found out by careful examination of the head.

Dizziness (giddiness, vertigo) is accounted for in different instances by either of four causes : mere weakness; disorder of the liver (biliousness,) and stomach; disease of the internal ear; disease of the brain. The last of these is the least common, unless in persons over sixty years of age.

Loss of speech {aphasia), or getting the wrong words instead of those intended, comes from a disorder of the brain. It is often accompanied by loss of power, especially in the right arm and leg. Loss of voice {aphonia) is another thing; resulting from thickening of the lining membrane of the windpipe {larynx), or paralysis of its muscles; or, in the dying or nearly dying state, extreme debility.