considerable influence in promoting animal life, by their action
upon respiration, and the circulation of the blood. Laughing exists
under all circumstances, independently of education or imitation. The
child of the negro slave, born only to inherit the toils and misery
of its parents, receives its master with a smile every time he enters
his kitchen or a negro-quarter. But laughing exists in infancy under
circumstances still more unfavourable to it; an instance of which is
related by Mr. Bruce. After a journey of several hundred miles across
the sands of Nubia, he came to a spring of water shaded by a few scrubby
trees. Here he intended to have rested during the night, but he had not
slept long before he was awakened by a noise which he perceived was made
by a solitary Arab, equally fatigued and half famished with himself, who
was preparing to murder and plunder him. Mr. Bruce rushed upon him, and
made him his prisoner. The next morning he was joined by a half-starved
female companion, with an infant of six months old in her arms. In
passing by this child, Mr. Bruce says, it laughed and crowed in his
face, and attempted to leap upon him. From this fact it would seem as
if laughing was not only characteristic of our species, but that it was
early and intimately connected with human life. The child of these Arabs
had probably never seen a smile upon the faces of its ferocious parents,
and perhaps had never (before the sight of Mr. Bruce) beheld any other
human creature.
Crying has a considerable influence upon health and life in children.
I have seen so many instances of its salutary effects, that I have
satisfied myself it is as possible for a child to "cry and be fat," as
it is to "laugh and be fat."
4. As children advance in life, the constancy of their appetites for
food, and their disposition to laugh and cry, lessen, but the diminution
of these stimuli is supplied by exercise. The limbs[94] and tongues of
children are always in motion. They continue likewise to eat oftener
than adults. A crust of bread is commonly the last thing they ask
for at night, and the first thing they call for in the morning. It
is now they begin to feel the energy of their mental faculties. This
stimulus is assisted in its force by the disposition to prattle, which
is so universal among children. This habit of converting their ideas
into words as fast as they rise, follows them to their beds, where we
often hear them talk themselves to sleep in a whisper, or to use less
correct, but more striking terms, by _thinking aloud_.
[94] Niebuhr, in his Travels, says the children in Arabia are taught to
keep themselves constantly in motion by a kind of vibratory
exercise of their bodies. This motion counteracts the diminution
of life produced by the heat of the climate of Arabia.
5. Dreams act at an early period upon the bodies of children. Their
smiles, startings, and occasional screams in their sleep appear to arise
from them. After the third or fourth year of their lives, they sometimes
confound them with things that are real. From observing the effects of
this mistake upon the memory, a sensible woman whom I once knew, forbad
her children to tell their dreams, lest they should contract habits of
lying, by confounding imaginary with real events.
6. New objects, whether natural or artificial, are never seen by
children without emotions of pleasure which act upon their capacity
of life. The effects of novelty upon the tender bodies of children
may easily be conceived, by its friendly influence upon the health of
invalids who visit foreign countries, and who pass months or years in a
constant succession of new and agreeable impressions.
III. From the combination of all the stimuli that have been enumerated,
human life is generally in excess from fifteen to thirty-five. It is
during this period the passions blow a perpetual storm. The most
predominating of them is the love of pleasure. No sooner does the system
become insensible to this stimulus, than ambition succeeds it in,
IV. The middle stage of life. Here we behold man in his most perfect
physical state. The stimuli which now act upon him are so far regulated
by prudence, that they are seldom excessive in their force. The habits
of order the system acquires in this period, continue to produce good
health for many years afterwards; and hence bills of mortality prove
that fewer persons die between forty and fifty-seven, than in any other
seventeen years of human life.
V. In old age, the senses of seeing, hearing, and touch are impaired.
The venereal appetite is weakened, or entirely extinguished. The pulse
becomes slow, and subject to frequent intermissions, from a decay in the
force of the blood-vessels. Exercise becomes impracticable, or irksome,
and the operations of the understanding are performed with languor and
difficulty. In this shattered and declining state of the system, the
absence and diminution of all the stimuli which have been mentioned are
supplied,
1. By an increase in the quantity, and by the peculiar quality of the
food which is taken by old people. They generally eat twice as much as
persons in middle life, and they bear with pain the usual intervals
between meals. They moreover prefer that kind of food which is savoury
and stimulating. The stomach of the celebrated Parr, who died in the
one hundred and fiftieth year of his age, was found full of strong,
nourishing aliment.
2. By the stimulus of the fæces, which are frequently retained for five
or six days in the bowels of old people.
3. By the stimulus of fluids rendered preternaturally acrid by age.
The urine, sweat, and even the tears of old people, possess a peculiar
acrimony. Their blood likewise loses part of the mildness which is
natural to that fluid; and hence the difficulty with which sores heal in
old people; and hence too the reason why cancers are more common in the
decline, than in any other period of human life.
4. By the uncommon activity of certain passions. These are either good
or evil. To the former belong an increased vigour in the operations of
those passions which have for their objects the Divine Being, or the
whole family of mankind, or their own offspring, particularly their
grand-children. To the latter passions belong malice, a hatred of the
manners and fashions of the rising generation, and, above all, avarice.
This passion knows no holidays. Its stimulus is constant, though varied
daily by the numerous means which it has discovered of increasing,
securing, and perpetuating property. It has been observed that weak
mental impressions produce much greater effects in old people than in
persons in middle life. A trifling indisposition in a grand-child, an
inadvertent act of unkindness from a friend, or the fear of losing a
few shillings, have, in many instances, produced in them a degree of
wakefulness that has continued for two or three nights. It is to this
highly excitable state of the system that Solomon probably alludes, when
he describes the grasshopper as burdensome to old people.
5. By the passion for talking, which is so common, as to be one of the
characteristics of old age. I mentioned formerly the influence of this
stimulus upon animal life. Perhaps it is more necessary in the female
constitution than in the male; for it has long ago been remarked, that
women who are very taciturn, are generally unhealthy.
6. By their wearing warmer clothes, and preferring warmer rooms, than in
the former periods of their lives. This practice is so uniform, that it
would not be difficult, in many cases, to tell a man's age by his dress,
or by finding out at what degree of heat he found himself comfortable in
a close room.
7. By dreams. These are universal among old people. They arise from
their short and imperfect sleep.
8. It has been often said, that "We are once men, and twice children."
In speaking of the state of animal life in infancy, I remarked that the
contractility of the animal fibres predominated over their sensibility
in that stage of life. The same thing takes place in old people, and it
is in consequence of the return of this infantile state of the system,
that all the stimuli which have been mentioned act upon them with much
more force than in middle life. This sameness, in the predominance of
excitability over sensibility in children and old people, will account
for the similarity of their habits with respect to eating, sleep,
exercise, and the use of fermented and distilled liquors. It is from
the increase of excitability in old people, that so small a quantity
of strong drink intoxicates them; and it is from an ignorance of this
change in their constitutions, that many of them become drunkards, after
passing the early and middle stages of life with sober characters.
Life is continued in a less imperfect state in old age in women than
in men. The former sew, and knit, and spin, after they lose the use of
their ears and eyes; whereas the latter, after losing the use of those
senses, frequently pass the evening of their lives in a torpid state
in a chimney corner. It is from the influence of moderate and gently
stimulating employments, upon the female constitution, that more women
live to be old than men, and that they rarely survive their usefulness
in domestic life.
Hitherto the principles I am endeavouring to establish have been applied
to explain the cause of life in its more common forms. Let us next
inquire, how far they will enable us to explain its continuance in
certain morbid states of the body, in which there is a diminution of
some, and an apparent abstraction of all the stimuli, which have been
supposed to produce animal life.
I. We observe some people to be blind, or deaf and dumb from their
birth. The same defects of sight, hearing, and speech, are sometimes
brought on by diseases. Here animal life is deprived of all those
numerous stimuli, which arise from light, colours, sounds, and speech.
But the absence of these stimuli is supplied,
1. By increased sensibility and excitability in their remaining senses.
The ears, the nose, and the fingers, afford a surface for impressions
in blind people, which frequently overbalances the loss of their
eye-sight. There are two blind young men, brothers, in this city, of
the name of Dutton, who can tell when they approach a post in walking
across a street, by a peculiar sound which the ground under their feet
emits in the neighbourhood of the post. Their sense of hearing is still
more exquisite to sounds of another kind. They can tell the names of a
number of tame pigeons, with which they amuse themselves in a little
garden, by only hearing them fly over their heads. The celebrated blind
philosopher, Dr. Moyse, can distinguish a black dress on his friends,
by its smell; and we read of many instances of blind persons who have
been able to perceive colours by rubbing their fingers upon them. One of
these persons, mentioned by Mr. Boyle, has left upon record an account
of the specific quality of each colour as it affected his sense of
touch. He says black imparted the most, and blue the least perceptible
sense of asperity to his fingers.
2. By an increase of vigour in the exercises of the mental faculties.
The poems of Homer, Milton, and Blacklock, and the attainments of
Sanderson in mathematical knowledge, all discover how much the energy of
the mind is increased by the absence of impressions upon the organs of
vision.
II. We sometimes behold life in idiots, in whom there is not only
an absence of the stimuli of the understanding and passions, but
frequently, from the weakness of their bodies, a deficiency of the
loco-motive powers. Here an inordinate appetite for food, or venereal
pleasures, or a constant habit of laughing, or talking, or playing with
their hands and feet, supply the place of the stimulating operations of
the mind, and of general bodily exercise. Of the inordinate force of the
venereal appetite in idiots we have many proofs. The cretins are much
addicted to venery; and Dr. Michaelis tells us that the idiot whom he
saw at the Passaic falls in New-Jersey, who had passed six and twenty
years in a cradle, acknowledged that he had venereal desires, and wished
to be married, for, the doctor adds, he had a sense of religion upon his
fragment of mind, and of course did not wish to gratify that appetite
in an unlawful manner.
III. How is animal life supported in persons who pass many days,
and even weeks without food, and in some instances without drinks?
Long fasting is usually the effect of disease, of necessity, or of a
principle of religion. When it arises from the first cause, the actions
of life are kept up by the stimulus of disease[95]. The absence of
food when accidental, or submitted to as a means of producing moral
happiness, is supplied,
1. By the stimulus of a full gall bladder. This state of the receptacle
of bile has generally been found to accompany an empty stomach. The
bile is sometimes absorbed, and imparts a yellow colour to the skin of
persons who suffer or die of famine.
2. By increased acrimony in all the secretions and excretions of the
body. The saliva becomes so acrid by long fasting, as to excoriate the
gums, and the breath acquires not only a f[oe]tor, but a pungency so
active, as to draw tears from the eyes of persons who are exposed to it.
3. By increased sensibility and excitability in the sense of touch. The
blind man mentioned by Mr. Boyle, who could distinguish colours by his
fingers, possessed this talent only after fasting. Even a draught of any
kind of liquor deprived him of it. I have taken notice, in my account of
the yellow fever in Philadelphia, in the year 1793, of the effects of a
diet bordering upon fasting for six weeks, in producing a quickness and
correctness in my perceptions of the state of the pulse, which I had
never experienced before.
4. By an increase of activity in the understanding and passions.
Gamesters often improve the exercises of their minds, when they are
about to play for a large sum of money, by living for a day or two upon
roasted apples and cold water. Where the passions are excited into
preternatural action, the absence of the stimulus of food is scarcely
felt. I shall hereafter mention the influence of the desire of life
upon its preservation, under all circumstances. It acts with peculiar
force when fasting is accidental. But when it is submitted to as a
religious duty, it is accompanied by sentiments and feelings which
more than balance the abstraction of aliment. The body of Moses was
sustained, probably without a miracle, during an abstinence of forty
days and forty nights, by the pleasure he derived from conversing with
his Maker "face to face, as a man speaking with his friend[96]."
[95] The stimulus of a disease sometimes supplies the place of food in
prolonging life. Mr. C. S----, a gentleman well known in
Virginia, who was afflicted with a palsy, which had resisted the
skill of several physicians, determined to destroy himself, by
abstaining from food and drinks. He lived _sixty_ days without
eating any thing, and the greatest part of that time without
tasting even a drop of water. His disease probably protracted his
life thus long beyond the usual time in which death is induced
by fasting. See a particular account of this case, in the first
number of the second volume of Dr. Coxe's Medical Museum.
[96] Exodus xxxiii, 11. xxxiv, 28.
I remarked formerly, that the veins discover no deficiency of blood in
persons who die of famine. Death from this cause seems to be less the
effect of the want of food, than of the combined and excessive operation
of the stimuli, which supply its place in the system.
IV. We come now to a difficult inquiry, and that is, how is life
supported during the total abstraction of external and internal stimuli
which takes place in asphyxia, or in apparent death, from all its
numerous causes?
I took notice, in a former lecture, that ordinary life consisted in
the excitement and excitability of the different parts of the body,
and that they were occasionally changed into each other. In apparent
death from violent emotions of the mind, from the sudden impression
of miasmata, or from drowning, there is a loss of excitement; but the
excitability of the system remains for minutes, and, in some instances,
for hours afterwards unimpaired, provided the accident which produced
the loss of excitement has not been attended with such exertions as are
calculated to waste it. If, for example, a person should fall suddenly
into the water, without bruising his body, and sink before his fears
or exertions had time to dissipate his excitability; his recovery
from apparent death might be effected by the gentle action of heat or
frictions upon his body, so as to convert his accumulated excitability
gradually into excitement. The same condition of the system takes place
when apparent death occurs from freezing, and a recovery is accomplished
by the same gentle application of stimuli, provided the organization
of the body be not injured, or its excitability wasted, by violent
exertions previously to its freezing. This excitability is the vehicle
of motion, and motion, when continued long enough, produces sensation,
which is soon followed by thought; and in these, I said formerly,
consists perfect life in the human body.
For this explanation of the manner in which life is suspended and
revived, in persons apparently dead from cold, I am indebted to Mr. John
Hunter, who supposes, if it were possible for the body to be _suddenly_
frozen, by an instantaneous abstraction of its heat, life might be
continued for many years in a suspended state, and revived at pleasure,
provided the body were preserved constantly in a temperature barely
sufficient to prevent re-animation, and never so great as to endanger
the destruction of any organic part. The resuscitation of insects, that
have been in a torpid state for months, and perhaps years, in substances
that have preserved their organization, should at least defend this bold
proposition from being treated as chimerical. The effusions even of the
imagination of such men as Mr. Hunter, are entitled to respect. They
often become the germs of future discoveries.
In that state of suspended animation which occurs in acute diseases, and
which has sometimes been denominated a _trance_, the system is nearly in
the same excitable state that it is in apparent death from drowning and
freezing. Resuscitation, in these cases, is not the effect, as in those
which have been mentioned, of artificial applications made to the body
for that purpose. It appears to be spontaneous; but it is produced by
impressions made upon the ears, and by the operations of the mind in
dreams. Of the actions of these stimuli upon the body in its apparently
lifeless state, I have satisfied myself by many facts. I once attended
a citizen of Philadelphia, who died of a pulmonary disease, in the 80th
year of his age. A few days before his death, he begged that he might
not be interred until one week after the usual signs of life had left
his body, and gave as a reason for this request, that he had, when a
young man, died to all appearance of the yellow fever, in one of the
West-India islands. In this situation he distinctly heard the persons
who attended him, fix upon the time and place of burying him. The horror
of being put under ground alive, produced such distressing emotions in
his mind, as to diffuse motion throughout his body, and finally excited
in him all the usual functions of life. In Dr. Creighton's essay upon
mental derangement, there is a history of a case nearly of a similar
nature. A young lady (says the doctor), an attendant on the princess
of----, after having been confined to her bed for a great length of
time, with a violent nervous disorder, was at last, to all appearance,
deprived of life. Her lips were quite pale, her face resembled the
countenance of a dead person, and her body grew cold. She was removed
from the room in which _she died_, was laid in a coffin, and the day for
her funeral was fixed on. The day arrived, and according to the custom
of the country, funeral songs and hymns were sung before the door. Just
as the people were about to nail on the lid of the coffin, a kind of
perspiration was observed on the surface of her body. She recovered.
The following is the account she gave of her sensations: she said, "It
seemed to her as if in a dream, that she was really dead; yet she was
perfectly conscious of all that happened around her. She distinctly
heard her friends speaking and lamenting her death at the side of her
coffin. She felt them pull on the dead clothes, and lay her in it. This
feeling produced a mental anxiety which she could not describe. She
tried to cry out, but her mind was without power, and could not act on
her body. She had the contradictory feeling as if she were in her own
body, and not in it, at the same time. It was equally impossible for
her to stretch out her arm or open her eyes, as to cry, although she
continually endeavoured to do so. The internal anguish of her mind was
at its utmost height when the funeral hymns began to be sung, and when
the lid of the coffin was about to be nailed on. The thought that she
was to be buried alive was the first which gave activity to her mind,
and enabled it to operate on her corporeal frame."
Where the ears lose their capacity of being acted upon by stimuli, the
mind, by its operations in dreams, becomes a source of impressions
which again sets the wheels of life in motion. There is an account
published by Dr. Arnold, in his observations upon insanity[97], of a
certain John Engelbreght, a German, who was believed to be dead, and who
was evidently resuscitated by the exercises of his mind upon subjects
which were of a delightful or stimulating nature. This history shall
be taken from Mr. Engelbreght's words. "It was on Thursday noon (says
he), about twelve o'clock, when I perceived that death was making his
approaches upon me from the lower parts upwards, insomuch that my whole
body became stiff. I had no feeling left in my hands and feet, neither
in any other part of my whole body, nor was I at last able to speak or
see, for my mouth now becoming very stiff, I was no longer able to open
it, nor did I feel it any longer. My eyes also broke in my head in such
a manner that I distinctly felt it. For all that, I understood what
they said, when they were praying by me, and I distinctly heard them
say, feel his legs, how stiff and cold they have become. This I heard
distinctly, but I had no perception of their touch. I heard the watchman
cry 11 o'clock, but at 12 o'clock my hearing left me." After relating
his passage from the body to heaven with the velocity of an arrow shot
from a cross bow, he proceeds, and says, that as he was twelve hours in
dying, so he was twelve hours in returning to life. "As I died (says
he) from beneath upwards, so I revived again the contrary way, from
above to beneath, or from top to toe. Being conveyed back from the
heavenly glory, I began to hear something of what they were praying for
me, in the same room with me. Thus was my hearing the _first_ sense I
recovered. After this I began to have a perception of my eyes, so that,
by little and little, my whole body became strong and sprightly, and no
sooner did I get a feeling of my legs and feet, than I arose and stood
firm upon them with a firmness I had never enjoyed before. The heavenly
joy I had experienced, invigorated me to such a degree, that people were
astonished at my rapid, and almost instantaneous recovery."
[97] Vol. ii. p. 298.
The explanation I have given of the cause of resuscitation in this
man will serve to refute a belief in a supposed migration of the
soul from the body, in cases of apparent death. The imagination, it
is true, usually conducts the whole mind to the abodes of happy or
miserable spirits, but it acts here in the same way that it does when it
transports it, in common dreams, to numerous and distant parts of the
world.
There is nothing supernatural in Mr. Engelbreght being invigorated by
his supposed flight to heaven. Pleasant dreams always stimulate and
strengthen the body, while dreams which are accompanied with distress or
labour debilitate and fatigue it.
LECTURE III.
GENTLEMEN,
Let us next take a view of the state of animal life in the different
inhabitants of our globe, as varied by the circumstances of
civilization, diet, situation, and climate.