It would be as foolish to depreciate the value as to underrate the danger of this, the most powerful and in many respects the safest of anæsthetics. Nothing else can do what opium can to relieve chronic, persistent, incurable nervous pain, to give sleep when sleeplessness is produced by suffering. The more potent anæsthetics, like chloroform, are applicable only to brief intense tortures, whose period can be foreseen or determined—to produce insensibility during an operation, or to mitigate the pangs of child-birth. Opium can relieve incurable chronic pain that would otherwise render life intolerable, and perhaps drive the sufferer to suicide; and this, if moderation be observed, and the necessary correctives employed, without impairing, as other narcotics would, the intellectual faculties. It is, moreover, as aforesaid, the quickest and surest cure for bronchial affections of every kind, and might not impossibly, as De Quincey thought, if used in time and with sufficient decision, prolong a life otherwise doomed, if it could not actually cure phthisis or consumption after the formation of tubercle has once begun. But its legitimate use is limited to three cases. It can relieve temporary neuralgic pain when cure would be slow, or while awaiting a curative operation. One peculiarity of neuralgic pain is its tendency to perpetuate itself. The nerves continue to thrill and throb because worn out by pain. Give them, through whatever agency, a brief period of rest, and it may well happen that, the temporary cause removed, the pain will not return. Secondly, opium is the one anæsthetic agency available to mitigate incurable and intolerable suffering. Not only can it render endurable a life that must otherwise be one continuous torture, till torture hastens death; but it may in many cases render that life serviceable as well as endurable. De Quincey gives the instance of a surgeon, suffering under incurable disease of an intolerably painful kind, who owed the power of steady professional work for more than twenty years to the constant use of opium in enormous quantities. Finally, when a working life draws near its natural close, when old age is harassed by the nervous consequences of protracted over-work or over-strain such as is often almost inseparable from the anxieties of business—the severe taxation of the mental powers by professional or literary labor—opium, given habitually in small quantities and under careful medical direction, often does what wine effects with less certainty and safety; gives rest and repose, calms an irritability of nerve and temper more trying to the patient himself than to those around him, and renders the last decade of a useful and honorable life much more comfortable, and no wit less useful or honorable, than it might otherwise have been.