referred only to the muscles, and the amount of exercise which a man
should take in a day is stated as equal to a certain number of
foot-pounds. The mere giving work to muscles is not, however, exercise
in the sanitary sense. A better definition is that of Du Bois
Reymond--viz. that "exercise is the frequent repetition of a more or
less complicated action of the body with the co-operation of the mind,
or of an action of the mind alone, for the purpose of being able to
perform such actions better." From this point of view it will be seen
that exercise relates quite as much to the nervous system as to the
muscles. When, for example, a student takes a walk over ground with
which he is familiar, and is at the same time so deeply engaged in
thought as to be practically unconscious of what he is doing, only
being recalled to himself, it may be, by arriving at his own door, the
exercise which he has had is but partial and insufficient. Going to
the extreme, we can, as Du Bois Reymond remarks, conceive of a man
with muscles individually exercised until they were like those of the
Farnese Hercules, and yet who would be unable to walk, much less
execute more complicated movements; for the proper co-operation of the
muscles, which is effected through the nervous system, is quite as
necessary as the force of their contraction.
The amount of exercise which is necessary for health varies with the
individual and with age, season, etc., so that it is difficult to
state any general rule upon this subject; but if stated in terms of
muscular force only, the estimate of Dr. Parkes seems a fair
approximation--viz. that every healthy man ought to take daily an
amount of exercise equivalent to 150 tons lifted 1 foot, or a walk of
about nine miles. The majority of trades and bodily occupations demand
at least this amount of work, but in some of them the greater part of
the exertion is made only by certain groups of muscles, and they are
carried on in crowded and {199} ill-ventilated shops. Such workmen, as
well as all who are engaged in sedentary pursuits, require exercise in
the open air--exercise which will bring into play the unused muscles
and will break the train of thought of the professional man.
One of the most important questions with regard to physical exercise
is the extent to, and manner in, which it should be provided for in a
proper system of education. One of the latest and most instructive
articles on this subject is that by Du Bois Reymond in the "Physiology
of Exercise," a translation of which is given in the _Popular Science
Monthly_ for July and August, 1882. He divides the physical training
which is more and more becoming a part of modern systematic education
into three classes: The first, the turning, or gymnastics of the
Germans; the second, the Swedish system, in which the exercises are
limited to very simple though varied movements; and the English
system, or rather want of system, consisting largely of athletic games
and contests of various kinds. His objection to the Swedish system is
that, while it strengthens the muscles, it does not increase the power
over composite movements; in other words, it does not exercise the
nervous system. Naturally, he prefers the German system to any other,
although admitting that the English meets better the demands arising
from our structure. "Were the end masterhood in running, jumping,
climbing, in dancing, fencing, riding, in swimming, rowing, or
skating, then nothing could be more advisable than to practise equally
the necessary concatenations in the actions of the ganglion cells,
without pausing at the not practically applicable preliminary and
intermediate steps of the German turning."
From a sanitary point of view, the gymnasium, as usually located and
managed, is by no means equivalent to out-of-door sports and contests,
although it is often the best substitute for them. The form of
exercise most used by men whose occupation does not involve bodily
labor is walking, and next to this riding. Whatever mode be selected,
it is very desirable that it should be taken for some other object
than that of the mere making muscular exertion, or otherwise it will
soon come to be looked upon as an unpleasant task, the time spent upon
which is given grudgingly; and it will be partially or wholly
abandoned as soon as the immediate discomfort which induced its use
has ceased.
It is not an uncommon error among men engaged in mental work to
suppose that they can, and ought to, take the same amount of exercise
which gives good results in those whose occupations involve physical
rather than mental effort, or to think that the more exercise they
take the more study or writing they are equal to. This is a grave
mistake. Expenditure of brain-tissue is not to be repaired by muscular
exertion, but by sleep and food, and exercise in the fresh air
sufficient to produce appetite and sufficient weariness to ensure
restful sleep is all that is necessary. For a time it is true that the
student or writer who has a well-developed body can continue to burn
the candle at both ends, and win literary honors while also standing
high as an athlete; but this surely leads to physiological bankruptcy
in the end.
It is to be remembered that good muscular development is not
necessarily synonymous with health, and that strength is not a
guarantee against disease. And, while it is true that in this, as in
most other matters of individual hygiene, each man must to a great
extent be a law to {200} himself, and learn by experience what kind of
exercise and how much of it he requires, yet the physician can often
supply the motive which was wanting, or check undue effort. Exercise
for the sake of health and comfort is not an end, but a means; yet if
this means can be made to secure to the patient an end agreeable and
pleasant in itself, so much the better.
XI. CONTAGION AND DISINFECTION.--By "contagion" we mean the
communication of disease from one person to another, either by direct
contact or through some medium, such as air, water, etc. It therefore
includes "infection," which is now generally used as a synonym for it.
The so-called infective diseases of modern German writers
(Infections-Krankheiten) include, besides what are commonly termed in
English, contagious diseases, the so-called miasmatic diseases.
The characteristic of a contagious disease is its specificity; that
is, the disease transmitted is always the same in its essential
characteristics. It does not, however, follow that all cases of the
disease are equally liable or have the same power to transmit it; in
other words, the degree of virulence of the contagiousness is not an
essential characteristic. That the same disease sometimes spreads
rapidly and is very fatal, and at other times seems hardly to have any
contagious properties and is very mild, has long been noticed, and has
been attributed to an unknown something called the medical
constitution of the place--the constitution médicale of French
writers. The true cause is probably very complex, but in some cases,
at all events, it seems to be due to difference in the contagion
itself. If we suppose this contagion to be a minute organism, it is
easy to form a theory as to the cause of these differences, but there
is much careful experimental work to be done before we shall have
positive knowledge on this point. The results obtained by Pasteur in
attenuating the virus of chicken cholera and splenic fever indicate
one line which these experiments will take, and the researches of Koch
point out another.
The diseases which spread by contagion until they form epidemics are
those which have from the earliest times attracted the most general
attention, and which have given rise to organized efforts for
prevention--_i.e._ to public hygiene.
They are also the diseases which have given rise to the most bitter
controversies among medical men as to the means of their propagation
and the best methods of prevention. Plague, cholera, yellow fever, and
typhus are those with regard to which this difference of opinion has
chiefly occurred--one party considering their chief cause to be
contagion, or specific germs derived directly or indirectly from the
bodies of the sick; the second party declaring that they are due to
filth plus an unknown something, which is variously termed epidemic
constitution, pandemic wave, Providence, or _x_. The great majority of
opinions at present is in favor of the view that they are all
contagious, but not all, or always, contagious from person to
person--that they spread from infected localities, which localities
receive their infection from cases of the disease. The best means of
dealing with them under ordinary circumstances are now tolerably well
understood, and where these means can be commanded--as, for instance,
among troops in time of peace--epidemics of these diseases can be
stopped with great precision and promptness by isolation and
disinfection.
{201} By "isolation" is meant not only the separation of the sick from
the well, but the isolation of the infected locality or water-supply
until it has been rendered harmless.
By "disinfection" is meant the destruction of the specific causes of
disease, and more especially of the infectious or spreading diseases.
A disinfectant is not necessarily an antiseptic or a deodorant, nor
are these last necessarily disinfectants. The best practical
antiseptic for sanitary purposes is cleanliness; the best
disinfectants are heat, bichloride of mercury, sulphate of iron,
chloride of zinc, sulphurous acid, chlorine, sunlight, and pure air,
and, for yellow fever, cold. With our present very imperfect knowledge
of the nature of specific causes of disease which we wish to destroy,
we have no means of determining the presence of these causes in or on
an article of clothing or of furniture, or in a room or other
locality, except by the production of their specific effects on man or
by inductive reasoning; in other words, we can only say that it is
more or less probable that such causes are present. This makes it
necessary, or at least expedient, to employ disinfectants in many
cases where the presence of such causes is doubtful. The practical
difficulties are, first, to bring the disinfecting agent into such
relation with the causes of disease that it can act upon them, and act
upon all of them; second, to avoid unnecessary destruction or injury
of things which should be preserved. The majority of the causes of
disease upon which we wish to act by disinfectants are probably minute
particles of solid or semi-solid matter which are living, and may be
conveniently designated by the word "_germs_." In the presence of
moisture the destruction of the vitality of these germs can be
effected with comparative ease and rapidity, but when they have become
dried, or, as in the case of the bacilli, are in the form of spores,
it is a more difficult matter.
To illustrate the methods to be pursued and the precautions to be
taken, let us suppose the physician to be called on for directions as
to the management of a case of scarlatina, the object being to prevent
its spread. The first thing to be done is to get the patient in a room
by himself, and to leave nothing in this room which is not necessary.
Remove the carpet, curtains, and all stuffed or upholstered furniture.
Let the nursing be done, as far as possible, by one person only, and
do not allow others, and especially children, to enter the room, no
matter if they have had the disease. The danger of contagion depends
upon particles coming from the skin and mucous membranes. All excreta,
and more especially the sputa or discharges from the mouth or nose,
are to be treated as dangerous. The excreta should be received in
vessels containing a solution of sulphate of iron, one and a half
pounds to the gallon. All clothing, towels, bed-linen, handkerchiefs,
napkins, etc. should be placed in a solution composed of four ounces
of sulphate of zinc and two ounces of common salt to the gallon of
water as soon as they are not needed for further use. Especial care
should be taken that none of these articles are removed from the room
while dry, and while they are in the room, and before they have been
moistened, they should not be shaken or disturbed more than is
absolutely necessary. If for any reason the zinc solution above
referred to is not at hand--which should very rarely be the case--the
clothing, etc. should be placed in a bucket, tub, or boiler containing
enough scalding water to entirely cover them, and be removed {202}
from the room in this vessel. All such articles should be boiled at
least one hour.
No sweeping or dusting in the ordinary way is to be done in the room;
dust and dirt are to be removed by damp cloths, which are to be
treated like the bedding and clothing. The great object is to prevent
as far as possible the production of dust in the atmosphere of the
room. The entire body of the patient, including head, face, and limbs,
should be kept thoroughly anointed with camphorated oil, vaseline, or
some similar substance, and especial care should be taken in this
respect during the period of convalescence so long as any roughness or
desquamation of the skin continues. No toys or books which it is
desired to preserve should be allowed to remain in the room, and under
no circumstances should books or toys be borrowed to amuse the child
if they are to be returned. The best way to disinfect such articles is
to burn them in the room.
When the patient is fully convalescent and all desquamation has
ceased, cleanse him thoroughly with a warm bath and soap for four
successive days. If at the end of that time no roughness of the skin
remains, he may be dressed in clean clothes and taken from the room,
for he is no longer a source of danger. The room itself and the
furniture are then to be thoroughly cleansed and disinfected. The
ceiling and walls, if of ordinary hard finish, are to be scraped and
whitewashed. All woodwork should be rubbed with damp cloths and the
floor well scrubbed. Care should be taken to remove all dust from the
ledges over windows and doors. All the cloths used in this cleansing
process are to be burned.
If these directions have been carefully carried out, there is no need
for further disinfection. But if upholstered furniture has been
allowed to remain in the room, or other articles which cannot be
burned or scrubbed or soaked in the zinc solution, it may be desirable
to attempt to disinfect the whole room and its contents by means of
chlorine or sulphurous acid gases. Of these, sulphurous acid gas is
the cheapest, and upon the whole the best, but it must be used in
large quantity, and for a longer time than is customary, if it is to
be relied upon. For this purpose all openings into the room should be
closed, and pillows, mattrasses, upholstered furniture, and articles
which cannot be treated with the zinc solution should be opened, so
that they may be exposed throughout to the fumes. The sulphur should
be burned in an iron pan or pot, placed in a tub containing water or
upon a large surface of sand. About 18 ounces of roll sulphur should
be used to each 1000 cubic feet of space, and after twenty-four hours
12 ounces more should be burned and the room be then closed for
twenty-four hours longer, after which it may be opened and aired. In
case of death the body should at once be wrapped in a sheet thoroughly
soaked with the chloride of zinc solution, and either be placed in an
air-tight coffin at once or be buried without delay. The funeral
should be strictly private, and the sheet referred to should not be
disturbed or the body exposed to view.
The cases most liable to spread the disease are those in which the
attack is very light and the child is not confined to its bed. It is
desirable that children in a house in which there are cases of scarlet
fever should not be allowed to attend school or mingle with other
children who have not had the disease.
With regard to disinfectants, it may be well to note that none of the
{203} various patent disinfectants are superior to bichloride of
mercury, chloride of zinc, sulphate of iron, chlorine, and sulphurous
acid; very few are equal to them, and none cost so little. As a
gaseous disinfectant for rooms, etc. chlorine is superior to
sulphurous acid, but it has the disadvantage of injuring metals, is
not so easily applied, and is more costly. It will destroy the
vitality of the spores of the bacilli more rapidly and certainly than
sulphurous acid, which last, to make sure work, must be exhibited for
a much longer period than is customary. I should not feel confident as
to the thorough disinfection by sulphurous acid of the hold of an
infected ship unless the fumes had been applied for sixty hours.
Carbolic acid as ordinarily used is an antiseptic rather than a
disinfectant. Its vapor in a sick room is absolutely useless. When
applied in strong solution it is effective, for a time at least, but
as thus used it is expensive, its odor is unpleasant to many, and
masks the odors from putrefying substances and excreta, etc., thus
preventing the warning which these odors would give. Its use is in
many cases very much like removing the rattle from the rattlesnake.
The suggestions made above for limiting the spread of scarlatina from
a case to be treated in the residence of the patient apply--with
certain modifications for each form of disease, which will readily
suggest themselves to the physician--to all the affections due to
portable contagia.
Among the poorer classes, however, it will often be found impossible
to obtain the separate room and service and the constant intelligent
care which are necessary to ensure the desired result; and in such a
case the patient should be removed to a hospital, for his own sake as
well as for that of the community. The utility of small hospitals for
infectious diseases is by no means generally understood, and very few
of our small cities and towns are provided with anything of the sort.
If the subject is urged on the authorities of a place, the reply will
be that it is an unnecessary expense, that the people would not go to
it, and that such an institution is in itself a source of danger. The
facts are, that such a hospital costs very little, and is the cheapest
insurance against epidemics which a town can have; if it is kept clean
and comfortable, the people will use it freely, and if properly
managed it does not offer the slightest danger to the vicinity. This
question will be further discussed in the last section of this paper.
The principles of isolation as applied to a single case as indicated
above may also be applied to infected localities in case of epidemics.
When taken in time, all diseases which depend upon particulate
contagia for their origin can be stamped out by isolation and
disinfection. Unfortunately, to effect this promptly and successfully
requires money, labor, and the co-operation of the well in the
vicinity; which last it is usually impossible to obtain voluntarily or
to compel sufficiently to secure the desired results. A question which
sometimes arises in case of epidemics, and with regard to the
necessity for which physicians will be consulted, relates to the
closure of the public schools. It is certain that the assemblage of
children in schools exerts a powerful influence on the spread of such
diseases as scarlet fever, diphtheria, and whooping cough. On the
other hand, the closure of the schools infringes upon the rights of a
large number of the community, and if long continued, as it sometimes
must be to be really efficacious, inflicts upon them {204} a permanent
loss. It is, moreover, a confession on the part of the authorities of
inability to induce or compel what must always be a comparatively
small part of the community to take the proper precautions. It is
never justifiable to close schools on account of small-pox, and where
there is a competent health authority supported by the influence of
the medical profession, it must be a very exceptional set of
circumstances which justifies their closure for diphtheria or
scarlatina.
It is not deemed expedient here to discuss the vexed question of
quarantine. It is more important against yellow fever than any other
disease, because every day of delay of the entrance of the disease
which it secures lessens largely the subsequent mortality, since the
duration of the disease is limited by frost. This is not the case with
cholera, and the mere keeping this disease out of a place for a few
weeks does not diminish its ravages when it has once gained an
entrance. To rely altogether on quarantine, either maritime or inland,
to keep yellow fever, cholera, or any other disease out of this
country is a far greater mistake than to neglect it altogether. The
practical way to isolate and quarantine is to get as close to the
affected spot as possible. Precautions at Havana for yellow fever, or
at Hamburg for cholera, are far more useful to the United States than
the same amount of work at our own ports can possibly be; really good
work in this direction must be not only national, but international.
XII. MENTAL CAUSES OF DISEASE.--A man may give too much attention to
his health and the means for its preservation, and the doing so is
both a sign and a cause of disease--probably oftener the former than
the latter, except in cases of psychological epidemics. The power of
expectant attention, especially if accompanied by belief or fear, to
produce derangement of function in the nervous system, and through
this to affect the circulatory and digestive systems, is well known to
medical men. The effects of an undue amount of brain-work, and
especially of the anxiety and worry which often accompany this when it
is specially directed to the acquiring of wealth, fame, or power, are
also familiar to physicians in our large cities. The analogies between
mental and physical exertion are close in some respects, and
especially as to the effects of over-exertion in a limited time under
the influence of excitement.
The danger from simple mental work, such as study, when there is no
excitement from a contest, is small, and depends mainly on lack of
physical exercise and consequent disorder of the digestive organs. The
risk of producing what Fothergill calls "physiological bankruptcy" is
greatest in the youth studying for a prize, the speculator, the man
who feels responsibility which he knows he probably cannot meet. The
danger of injury from overwork under excitement is a very real one in
many of our schools, and, while the evil results are most apparent in
girls of the middle and upper classes, the boys and the young men also
suffer. The system of pass examinations, in which the standing of the
pupil is to be determined, not from the average results of his daily
recitations, but from a single examination at the end of the year,
produces the greatest risks to health; and this is especially the case
where the ambition and pride of the children are stimulated by
competition for prizes, medals, etc. Such systems of grading by a
single final examination should not be used in ordinary schools, and
for some pupils there will always be a risk to health connected with
them even when they are of age. No doubt the stimulus of {205}
competition is useful with the majority of children as well as of
adults, but with some of them it is pretty sure to go too far.
The symptoms produced by undue mental strain are familiar to all
physicians, and there is usually little difficulty in tracing the
effect to the cause when attention has been directed to the matter; in
fact, the patient himself usually knows very well the cause of his
troubles. The remedy is, of course, rest--but that does not mean
idleness. In speaking of occupation, allusion has been made to the
fact that the physician must at times advise his patient as to the
adoption of some pursuit, and in cases of this kind such advice is
also useful.
The effects of mental strain are often mingled with, and aggravated
by, those of stimulants which have been used to spur the flagging
energies. Alcohol, tobacco, opium, or coffee used in this way finally
increase the very discomforts which at first they relieved.
II. Personal Hygiene in its Relations to the Practice of Medicine.