The remainder, five in number, are the opium alkaloids, which act generally upon the whole system, but particularly, in their immediate phenomena, upon the brain. I mention them in the ascending order of their nervine power; narcotin; codein; opianin; metamorphia, and morphia.
The first of these the poppy shares in common with many other narcotic plants—tobacco the most conspicuous among the number. In its anti-periodic effects on the human system it has been found similar to quinia, and it is an undoubted narcotic poison acting on the nerves of organic life, though, compared with its associates in the drug, comparatively innocent.
The remaining four act very much like morphia, differing only in the size of the dose in which they prove efficient. Most perfectly fresh constitutions feel a grain of morphia powerfully; metamorphia is soporific in half-grain doses; [Footnote: American Journal of Pharmacy, September, 1861.] opianin in its physical effects closely approximates morphia; codein is about one-fifth as powerful; a new subject may not get sleep short of six grains; its main action is expended on the sympathetic system. It does not seem to congest the brain as morphia does; but its action on the biliary system is probably little less deadly than that of the more powerful narcotic.
Looking at the marvellous complexity of opium we might be led to the apriori supposition that its versatility of action on the human system must be equally marvellous. Miserably for the opium-eater, fortunately for the young person who may be dissuaded from following in his footsteps, we are left in no doubt of this matter by the conclusions of experience. In practical action opium affects as large an area of nervous surface, attacks it with as much intensity, and changes it in as many ways as its complexity would lead us to expect. I have pointed out the existence in opium of a convulsive poison congeneric with brucia. The other chief active alkaloids, five in number, are those which specially possess the cumulative property. Poisons of the strychnia and hydro-cyanic acid classes (including this just mentioned opium alkaloid, thebain) are swifter agents; but this perilous opium quintette sings to every sense a lulling song from which it may not awake for years, but wakes a slave. Every day that a man uses opium these cumulative alkaloids get a subtler hold on him. Even a physician addicted to the practice has no conception how their influence piles up.
At length some terrible dawn rouses him out of a bad sleep into a worse consciousness. Though the most untechnical man, he must already know the disorder which has taken place in his moral nature and his will. For a knowledge of his physical condition he must resort to his medical man, and what, when the case is ten years old, must a practitioner tell the patient in any average case?
"Sir, the chances are entirely against you, and the possession of a powerfully enduring constitution, if you have it, forms a decided offset in your favor."
He then makes a thorough examination of him by ear, touch, conversation. If enough constitution responds to the call, he advises an immediate entrance upon the hard road of abnegation.
If the practitioner finds the case hopeless he must tell the patient so, in something like these words:
"You have either suffered a disorganization of irreproducible membranes, or you have deposited so much improper material in your tissue that your life is not consistent with the protracted pain of removing it.
"One by one you have paralyzed all the excretory functions of the body. Opium, aiming at all those functions for their death, first attacked the kidneys, and with your experimental doses you experienced a slight access of dysouria. As you went on, the same action, progressively paralytic to organic life, involved the liver. Flatulence, distress at the epigastrium, irregularity of bowels, indicated a spasmodic performance of the liver's work which showed it to be under high nervous excitement. Your mouth became dry through a cessation of the salivary discharge. Your lachrymal duct was parched, and your eye grew to have an arid look in addition to the dullness produced by opiate contraction of the pupil.