sthenic disease, I now proceed to the consideration of the other
powers. Of the articles of diet, the only food in danger of being too
stimulant, is perhaps flesh or land animal food, used in too great
quantity, particularly when seasoned, a preparation which adds much
to its stimulant power. Spirituous and vinous liquors, let them be
ever so weak or much diluted, stimulate more quickly, and more
readily than seasoned food, and their stimulus is in proportion to
the quantity of alcohol which they contain. These substances, when
conjoined with rich food, must bring on a predisposition to sthenic
disease, in almost any constitution, particularly in the young and
healthy, and, in many instances, those diseases actually take place;
or should this not be the case, should the person avoid, or escape
the effects of inflammatory diseases, the excitability will be
exhausted, and diseases of indirect debility, such as gout, apoplexy,
indigestion, palsy, &c. will take place.
These stimulants are never necessary to a good constitution, and
their effects will always, sooner or later, be experienced: for
though a person with a good constitution may continue for years to
indulge in the pleasures of the bottle, or the luxuries of the table,
depend upon it that a continuance of them will sap the vigour of the
strongest constitution that ever existed.
As nothing contributes more to the health of the body than moderate
and frequently repeated exercise, which rouses the muscles to
contraction, and promotes the circulation of the blood in the veins
towards the heart: it thus produces excitement; but an excess of it
will produce sthenic diathesis; and, if carried to great excess, it
will produce a state of indirect debility, or exhausted excitability.
When any, or all of these exciting powers act too strongly on the
body, the first effect they produce is a preternatural acuteness of
all the senses; the motions, both voluntary and involuntary, are
performed with vigour, and there is an acuteness of genius and
intellectual power. In short, every part of the body seems in a state
of complete vigour and strength; that this is the case with the heart
and arteries, appears from the strong and firm pulse; in the stomach
it is shown by the appetite; and, in the extreme parts, by the ruddy
colour and complexion. In short, every appearance marks vigour of the
body, and abundance of blood. Could the body be kept in this state,
nothing could be more to be desired; this, however, is impossible;
the excitement, though still within the bounds of health, has
overstepped the point of good health, and is verging fast to
predisposition to sthenic disease; so that, to secure a permanent
state of health, it is always better to keep the excitement rather
under the middle point, or 40 degrees, than above it. During the
predisposition to sthenic disease, which is produced by the longer
continued, or increased action of these powers, no symptoms of
disease appear; but shortly after, disturbed sleep, depressed
spirits, languor, a sense of fulness, heaviness, particularly after
eating, show that this sthenic state cannot be further increased with
impunity. The least increase of sthenic diathesis now brings on a
disturbance of the functions, or actual disease; the commencement of
which is generally a shivering, and a sense of cold; thirst and heat
succeed; and then generally a pain in some part, either external or
internal: costiveness generally attends this state, the urine is
clear, and secreted in small quantity; memory and imagination become
diminished, and there is generally less appetite for food.
In peripneumony, inflammatory sore throat, and acute rheumatism,
there is an inflamed condition of the lungs, of the parts about the
throat, or of the muscles of the extremities: this shows that the
excitement here is greater than in other parts of the body; but it is
still increased or too great in every part, only those parts which
give the peculiar character to the disease are more affected than
other parts of the body, by being more exposed to the exciting
causes: thus, if a person be in perfect health, or a little below, he
will not be easily affected by any of the exciting causes of sthenic
disease, unless their application be very violent; he will go into a
warm room out of the cold air, and feel no other effect than a
pleasant glow: but if, by high living, or other means, he is brought
near the point of predisposition to sthenic disease, then the
slightest additional stimulus will bring it on, and if the throat has
been exposed to the application of cold, and the person comes
afterwards into a heated room, an inflammation of the parts about the
throat, or an inflammatory sore throat, accompanied by a sthenic
diathesis of the whole system, will be the consequence. This cannot
be cured by merely diminishing the excitement of the part, while the
excitement of the whole system remains: if we apply leeches to the
throat in this state, to diminish the quantity of blood, we only
debilitate the vessels, while fresh quantities of blood are poured
into them from the too full vessels of the body; even if we could
thus remove the sthenic diathesis of the part, we should go but a
little way towards removing the inflammatory disease, which
universally pervades the system.
The mode to be pursued therefore is, to take a quantity of blood from
the body, by opening a vein; to keep the body cool, by remaining in a
room where the temperature is at temperate, or a little below; by
abstaining from animal food, and from spirituous or fermented
liquors; and by the exhibition of purgatives, or at least of
laxatives. Then leeches or blisters applied to the part affected will
produce a good effect; and even stimulant applications to the
inflamed part may be advantageous; for a topical inflammation, as we
shall afterwards have occasion to see, depends on a debilitated state
of the minute vessels of the part, while at the same time the action
of the whole system is increased.
Besides the energy of the exciting hurtful powers, which I have
mentioned, there is in the parts which undergo the inflammation, a
greater sensibility, or an accumulated excitability; by which it
happens that some are more affected than the rest. To this we may
add, that whatsoever part may have been injured by inflammation, that
part in every future sthenic attack is in more danger of being
inflamed than the rest. Hence inflammatory sore throat, rheumatism,
and some other complaints of the kind, when once they have
supervened, are very apt to recur.
Among the sthenic or inflammatory diseases may be enumerated
rheumatism, catarrh, cynanche, or sore throat, scarlet fever,
inflammations of the brain, stomach, lungs, &c. &c.
Many of the contagious diseases, particularly small pox and measles,
produce a sthenic state, and are to be cured, or their action
moderated, by the debilitating plan which has been pointed out; and
particularly by a moderate, constant, and equable diminution of
temperature. Hence the violence of these diseases is greater when
they attack a person already predisposed to sthenic diathesis, but
much more mild when the excitement is rather under par.
LECTURE XII.
ON INFLAMMATION AND ASTHENIC DISEASES.
The last lecture was taken up chiefly with an account of sthenic
diseases, or those depending on too great a degree of excitement, and
which have been generally, but improperly, called inflammatory or
phlogistic. In that lecture I attempted to show, that when the
natural exciting powers, which support life, act with too much power,
or particularly if we employ any stimulants not natural to the body,
the functions both of body and mind become increased in vigour; but
if the exciting causes are continued and increased, the functions
become disturbed, and their action becomes painful and distressing.
This state, which is called sthenic diathesis, is often accompanied
by a redness, swelling, pain, and increased heat of some particular
part: these symptoms constitute what is usually termed an
inflammation of the part.
The method of cure in sthenic diseases was shown to be, by reducing
or moderating the action of the exciting powers; by keeping the body
cool; abstaining from high seasoned, and, in general, from animal
food; by the use of purgatives, and in many cases by diminishing the
quantity of blood in the body. I mentioned likewise, that it would be
but of little use to attempt to subdue the excitement of the inflamed
part, unless the excitement of the whole system was previously
diminished; but that after a general bloodletting, stimulant remedies
applied to the inflamed part, might be employed with success. This is
strictly agreeable to experience, but at first sight seems so very
contrary to the principles that have been advanced, that I shall
endeavour to explain the phenomena of inflammation, which do not seem
to be in general well understood.
All kinds of inflammation agree, in being attended with redness,
increased temperature, pain, and swelling; but they vary according to
the situation and texture of the part affected. All parts of the
body, excepting the cuticle, nails, hardest part of the teeth, and
hair, are subject to inflammation.
Among the causes of these complaints, may be enumerated too full a
diet, particularly too free a use of fermented liquors, and whatever
increases the impetus of the blood towards the part, as mechanical
and chemical irritation, and sudden changes of temperature,
particularly from cold to heat.
To explain the nature of inflammation, it may be observed, that such
is the wise constitution of the animal body, that whatever injures
it, excites motions calculated to correct or expel the offending
cause. Thus if an irritating substance is received into the stomach,
it excites vomiting; if into the lungs, a violent fit of coughing is
excited, and if into the nostrils, sneezing is the consequence. In
such cases we can readily trace the motions excited, and the manner
in which they act; but cannot trace the manner in which the offending
cause excites these motions.
Now if it can be shown that inflammation, like vomiting and coughing,
is an effort of the system to remove an offending cause, and if we
can trace every step of this operation, with the exception of the
changes induced on the nervous system, we shall understand the nature
of inflammation as completely as that of any function of the body.
The circumstance the most difficult to explain, is the increased
redness of the part affected, which can only depend on an increased
quantity of blood in the vessels. This has been supposed to depend
upon an increased action of the vessels of the part; but that this is
not the case, must be evident from what was said when we were
speaking of the circulation of the blood. It was shown, that the
circulation could not be carried on by the mere force of elasticity
alone; this force, were it perfect, would produce no effect; but as
there is no body with which we are acquainted that is perfectly
elastic; so the coats of the arteries are very far from being so,
hence their effect as elastic tubes will be to diminish the force of
the heart, instead of adding to it; for a certain quantity of this
force will be spent in distending the vessels, which, were they
perfectly elastic, would be restored to them, but as this is not the
case, this force is by no means restored. Indeed a variety of
considerations, observations, and experiments, tend to prove, that
the vessels are endowed with a power very different from elasticity,
which differs only in degree from that of the heart; in short, they
are possessed of muscular power.
After each contraction of the muscular coat, the elastic will act as
its antagonist, and enlarge the diameter, till the vessel arrive at a
mean degree of dilatation, but after this there is no further power
of distention inherent in the vessel. The action of the elastic coat
ceases; and no one will assert that a muscular fibre has power to
distend itself.
The only power by which the vessel can be further distended, is the
vis a tergo: after the vessel arrives at its mean degree of
dilatation, both the elastic and muscular coats act as antagonists to
the vis a tergo, or force which propels the blood into, and thus
tends further to dilate the vessel. If then the vis a tergo become
greater than in health, the powers of resistance inherent in the
vessels remaining the same; or if the latter be weakened, the vis a
tergo, or propelling force, remaining the same, the vessel must
suffer a morbid degree of dilatation. These appear to be the only
circumstances under which a vessel can suffer such dilatation.
But if, while the powers of the vessels remain the same, the vis a
tergo, or propelling force, be diminished, or the propelling force
remaining the same, the power of the vessels become increased; then
an opposite condition or state of the vessels, viz. a preternatural
diminution of their area, will take place.
In the one case the distending force bears too great a proportion to
the resisting force; and preternatural distention is the consequence.
In the other the resisting force bears too great a proportion to the
distending force, and preternatural contraction is the consequence.
It is not necessary that the vessels should be in a state of greater
debility than in health, in order that an inflammation or distention
may take place: it is only necessary that the proportion which their
action bears to the propelling force be less than in health. If the
propelling force remain the same, the vessels must be in a state of
debility before an inflammation can take place; but if the propelling
force be increased by a fullness of the vessels and sthenic
diathesis, inflammation may take place, although the vessels of the
part act as powerfully as in health, or more so. But after
inflammation has taken place, as the vessels are preternaturally
distended, they must also be debilitated.
The degree of inflammation is not however proportioned to the
debility of the minute vessels of an inflamed part, but to the
diminished proportion of their power to the propelling force.
When, therefore, inflammation arises from an increased action of the
arterial system, or an increased propelling force, while the force of
the capillaries or minute vessels remains the same, it constitutes
what is called an active inflammation, and is to be cured by general
bleedings, and then by gentle applications of tonics to the part, to
increase its action; but when it arises from a debility of the minute
vessels, without any increase of the propelling force, it forms what
is known by the name of passive inflammation; in which general
bleeding is not required, but the application of stimulants and
tonics to the inflamed part to enable the vessels to recover their
lost tone, and restore the balance between their action and the vis a
tergo. From what has been said, it must be evident, that if
inflammation depend on the diminished proportion of the power of the
capillaries to the propelling force, it will be more apt to supervene
under the three following circumstances.
1. In a state of plethora, because then all the vessels are over
distended, and consequently any cause tending further to distend
them, whether it be a cause which debilitates them, or increases the
propelling force, will be more felt than in health.
2. In a state of general debility, because the vital powers in any
part are more readily destroyed than in health.
3. In a state of general excitement, because then the propelling
force is every where strong, and consequently apt to occasion
distention of the vessels, wherever any degree of debility occurs.
These are the states of the system which are found to predispose to
inflammation. In the first and last, the inflammation is generally of
that kind, which is termed active: the propelling force is
considerable, and the larger arteries are readily excited to
increased action. In the second state the inflammation is of the
passive kind.
This is not merely a useless physiological disquisition; it is of the
greatest use in directing our practice; and teaches us that, in
passive inflammation, which has all the symptoms of active, and
therefore shows in a striking point of view the fallacy of symptoms,
we shall not succeed by applying leeches, and other debilitating
means, to the inflamed part; on the contrary, we shall aggravate the
complaint; and the cure must be effected by stimulants applied to the
part.
As an instance of this kind of inflammation, I may mention that kind
of ophthalmia or inflammation of the eyes, which is of long standing,
and which not only resists the powers of leeches and blisters, but is
increased by them. I have frequently been consulted by patients, who
had for months been under the debilitating plan, without any benefit;
and who have been relieved almost instantly by the application of
electricity and a stimulating lotion, which restored the tone of the
debilitated vessels of the sclerotic coat, and enabled them to expel
their overcharged contents; and the balance between their action and
the propelling force being restored, the inflammation disappeared.
Indeed the effects of electricity in these kinds of inflammations are
wonderful: it seems to act almost by a charm, so quickly does the
inflammation subside; but when we understand the nature of this kind
of inflammation, it is nothing but what we might expect from its
action.
I have been thus minute on the subject of inflammation, because the
theory of it, which I have attempted to defend, differs considerably
from the commonly received opinions. I shall now proceed to consider
the nature of asthenic diseases.
From what has been already said, it must be evident that the causes
of diseases which we have assigned, are very different from those
delivered by physicians who preceded Dr. Brown. Some physicians
imagined that diseases were caused by a change in the qualities of
the fluids, which became sometimes acid, and sometimes alkaline; or
on a change of figure of the particles of the blood: some imagined
diseases to be owing to a rational principle, which they called the
vis medicatrix naturae, which governed the actions of the body, and
excited fever or commotion in the system to remove any hurtful cause,
or expel any morbid matter, which might have insinuated itself into
the body. Others supposed many diseases to arise from a constriction
of the extreme vessels by cold; or from a spasm of them, which was a
contrivance of the vis medicatrix, to rouse the action of the heart
and arteries to remove the debility induced.
We have seen, however, that health and diseases are the same state,
and depending upon the same cause; viz. excitement, but differing in
degree; and that the powers producing both are the same, sometimes
acting with a proper degree of force: at other times either with too
much, or too little.
We shall now examine how the diminished actions of the different
exciting powers produce asthenic disease; and we shall take them in
the same order as when we were speaking of sthenic diseases. It must
be recollected however that an asthenic state, or a state of
debility, may be produced in two ways. First, by directly diminishing
the action of the exciting powers. Secondly, by exhausting the
excitability, by a strong or long continued stimulant action. The
former state is called direct debility, and the latter indirect
debility. This is not merely a distinction without a difference, the
body is in very different states, under these two different forms of
disease. In the former case, the excitability is abundant, and highly
susceptible of the action of stimulants. In the latter, it is
exhausted, and the body has very little susceptibility.
Cold, or a diminution of heat, carried beyond a certain degree, is
unfriendly to all animals. Dr. Beddoes has shown very clearly in his
Hygeia, that it is the cause of a great many diseases which take
place at boarding schools, and that it there gives origin to a great
number of diseases that afterwards arise, and, indeed, not
unfrequently ruins the constitution. It produces relaxation of the
vessels, asthenic or passive inflammation, and even gangrene. He has
shown that in most schools children are afflicted with chilblains
from this cause; this is a case of passive inflammation, but is only
a symptom of the general debility induced, which shows itself
afterwards by the production of other symptoms. Hence it is necessary
for the preservation of health, that the temperature of school rooms
should always be kept equable, and regulated by means of a
thermometer. It should not exceed 50 degrees, nor should it be
allowed to fall much below it. If precautions of this kind are
thought to be necessary, and practised with uncommon attention, in
places where vegetables are reared, surely they ought not to be
neglected in those seminaries where the human species are to be
brought to maturity, and a good constitution established.
But though I have no doubt whatever, that this equable temperature
would prevent a number of diseases, which originate in too low a
temperature, yet I am far from wishing to have it thought that I
would not induce a hardy state of the constitution, which would
enable it to bear the vicissitudes to which it must be exposed in its
journey through life, by every means in my power. Hardiness is the
most enviable of all the attributes of animal nature, and can neither
be acquired, nor recovered when it is lost, but upon certain terms,
to which many people submit with reluctance, because they must give
up many indulgences and gratifications with which it is utterly
inconsistent.
One of the causes that chiefly contributes to reduce persons living
in affluence below the standard of hardiness, is the dependence they
place on a considerable degree of external warmth, for preserving a
comfortable state of sensation. From what has been said again and
again in some of the latest of these lectures, it must be evident
that continued warmth renders the living system less capable of being
excited to strong, healthy, and pleasant action: heat in excess,
whether it may be excess of duration or intensity, constantly
debilitates, by exhausting the excitability of the system, and thus
producing a state of indirect debility. Every muscle steeped in a
heated medium, whether of air or water, loses much of its
contractibility. A heart kept in heated air, or put in hot water,
will not contract on the application of a stimulus; even the limb of
a frog, when heated in this manner, ceases to move on the application
of the galvanic exciters. Every nerve grows languid, and when it does
become excited, it acquires a disposition to throw the moving fibres,
with which it is connected, into starts, twitchings, and other
irregular convulsive motions. Though therefore nothing can more
contribute to the health of the body than a moderate and well
regulated temperature, about 48 or 50 degrees, sometimes for a short
interval a little lower, when exercise is taken at the same time, yet
when we consider the life led by persons of fashion, we should hope
that it proceeded from ignorance of these consequences; so
diametrically opposite is it to the dictates of nature and reason.