Acute disease is apt to alter this more than that which is chronic ; but it is often changed in both. An anxious or distressed expression giving way to serenity is always a good sign, unless it be the result of morti-fication or palsy coming on.

Great anxiety is seen especially in organic diseases of the heart, and in acute disorders of the abdomen, as well as in melancholy.

Terror belongs habitually to delirium tremens, also called mania-a-potu, or the horrors. 480

Rage is now and, then seen in insanity, and in some, not all, cases of hydrophobia.

Insane persons, although not always very peculiar in countenance, have mostly an expression by which their derangement can be recognized by those accustomed to observing it.

Collapse, that is, extreme prostration, as from the shock of a railroad accident, an attack of cholera, or the dying state from any cause, has its own characteristic expression, more easily understood when seen than described. Shrunken cheeks, pale or livid, with mouth drawn down at the corners, and white, glassy eyes; these with clammy coldness to the touch, gasping respiration, and a thready or absent pulse at the wrist, mark this condition.