DIFFERENCES IN THE ACTION OF OPIUM AND ALCOHOL.
The _modus operandi_ of opium upon the body is considerably different
from that of alcohol. The latter intoxicates chiefly by acting _directly_
upon the nerves, the former by acting _secondarily_ upon them, through
the medium of absorption. This is easily proved by injecting a quantity
of each into the cellular tissue of any animal, and comparing the
effects with those produced when either is received into the stomach. M.
Orfila[23] details some interesting experiments which he made upon dogs.
In applying the watery extract of opium to them in the first manner,
(by injection into the cellular tissue,) immediate stupor, convulsions,
and debility ensued, and proved fatal in an hour or two. When, on the
contrary, even a larger quantity was introduced into the stomach of
the animal, it survived ten, twelve or eighteen hours, although the
œsophagus was purposely tied to prevent vomiting. The operation of
alcohol was the reverse of this; for, when injected into the cellular
substance, the effects were slight; but when carried into the stomach,
they were powerful and almost instantaneous. This proves that opium
acts chiefly by being taken up by the absorbents, as this is done much
more rapidly by the drug being directly applied to a raw surface than
in the stomach, where the various secretions and processes of digestion
retard its absorption. Besides, alcohol taken in quantity produces
instant stupefaction. It is no sooner swallowed than the person drops
down insensible. Here is no time for absorption; the whole energies
of the spirit are exerted against the nervous system. The same rapid
privation of power never occurs after swallowing opium. There is always
an interval, and generally one of some extent, between the swallowing and
the stupor which succeeds. Another proof that opium acts in this manner,
is the circumstance of its being much more speedily fatal than alcohol,
when injected into the blood vessels. Three or four grains in solution,
forced into the carotid artery of a dog, will kill him in a few minutes.
Alcohol, used in the same manner, would not bring on death for several
hours.
In addition it may be stated, that a species of drunkenness is produced
by inhaling the gas of intoxicating liquors. Those employed in bottling
spirits from the cask, feel it frequently with great severity. This
proves that there is a close sympathy between the nerves of the nose and
lungs, and those of the stomach. From all these circumstances, it is
pretty evident that intoxication from spirits is produced more by the
direct action of the fluid upon the nerves of the latter organ, than by
absorption.
Mr. Brodie supposes that there is no absorption whatever of alcohol, and
supports his views with a number of striking facts.[24] This, however,
is a length to which I cannot go. I am inclined to think that though
such absorption is not necessary to produce drunkenness, it generally
takes place to a greater or lesser degree; nor can I conceive any reason
why alcohol may not be taken into the circulation as well as any other
fluid. My reasons for supposing that it is absorbed are the following:—1.
The blood, breath, and perspiration of a confirmed drunkard differ
from those of a sober man; the former being darker, and the two latter
strongly impregnated with a spirituous odour. 2. The perspiration of
the wine-drinker is often of the hue of his favourite liquor; after a
debauch on Port, Burgundy, or Claret, it is not uncommon to see the shirt
or sheets in which he lies, tinted to a rosy colour by the moisture
which exudes from his body. 3. Madder, mercury, and sulphur are received
into the circulation unchanged; the former dyeing the bones, and the
others exhaling through the pores of the skin, so as to communicate
their peculiar odours to the person, and even discolour coins and other
metallic substances in his pockets. The first of these reasons is a
direct proof of absorption: the second shows, that as wine is received
into the circulation, and passes through it, alcohol may do the same; and
the third furnishes collateral evidence of other agents exhibiting this
phenomenon as well as spirituous liquors. The doctrine of absorption is
supported by Dr. Trotter,[25] who conceives that alcohol de-oxygenizes
the blood, and causes it to give out an unusual portion of hydrogen gas.
The quantity of this gas in the bodies of drunkards is so great, that
many have attempted to explain from it the circumstances of _spontaneous
Combustion_, by which it is alleged, the human frame has been sometimes
destroyed by being burned to ashes.