We call those diseases epidemic and common, that attack many persons
together; which, having a common origin, have also a common cause.
Common diseases are produced by common food of a bad quality, drinking
of bad water, inordinate fatigue, the want of the customary exercise,
deprivation or repletion from the prevalence either of a famine or of
great abundance. The nature of the country will also often occasion
common diseases, either from its lying adjacent to marshes, or to some
deep pit, which emits a deleterious and pernicious exhalation. These
things are constantly occurring. But the atmosphere which surrounds
us may alter the temperaments, by being hotter, colder, or more humid
than ordinary. For to other causes we are not all exposed together,
nor do we come in contact with them for the whole day; but the ambient
air is diffused around all, and is inhaled by respiration. Now, the
bodies of animals must undergo a change along with these changes as
to temperature. He, therefore, who is acquainted with these matters,
will not only be able to predict the diseases which are to arise from
every state of the atmosphere, but will be able also to prevent them by
substituting a counteracting regimen to the intemperament of the air.
Wherefore, those bodies which are disposed to a certain disease, from
a peculiar intemperament, will be affected by a similar temperature
of the surrounding air. But those of an opposite temperament to the
atmosphere will not only not be hurt but will be improved; the excess of
their intemperament being overcome by the opposite excess. He that is
acquainted with these things will preserve the health, by superinducing
the contraries to the constitution of the body; sometimes perhaps using
refrigerants, and sometimes heating things, cooling with water, using
restricted exercise and food, and plenty of dilution; and warming, by
means of increased clothing, exercise, more food and less drink. And, by
kindling a great pile, one may change the air from a humid state to that
which is dry and hot, as they say was done by Acron of Agrigentum.
* * * * *
COMMENTARY. This Section is mostly taken from Oribasius (Synops. vi, 24,
and Euporist. 1.)
The works of Hippocrates contain many interesting remarks on the origin
and nature of epidemics. He states that diseases in general may be
said to arise either from the food we eat or the air we breathe. When,
therefore, a disease seizes on a multitude of persons of different
ages, sexes, and habits, he justly infers that it must arise from the
latter cause. (See de Flatibus, Epidem. cum Commentariis Galeni.) The
fevers described by Hippocrates, in his ‘Books of Epidemics,’ are in
general intermittent and remittent fevers. In his first and third books
he describes forty-two cases of fever, twenty-five of which had a fatal
termination. They had evidently been selected from a larger number.
The descriptions are rigidly confined to a detail of the characters of
the season and the symptoms of the epidemic. In general, scarcely any
remedial means are mentioned. In some of the cases slight exanthemata
speedily disappearing are mentioned among the symptoms. These are more
likely to have been _petechiæ_ than the typhous eruption. It is reported
of Hippocrates, that, like Acron of Agrigentum, he changed the morbific
state of the atmosphere at Athens by kindling fires. (Galen, Therap. ad
Pison; Aëtius, v, 94.) Acron’s method of purifying the atmosphere is
mentioned by Plutarch (de Iside et Osiride.) For an account of Acron,
see Fabricii (Biblioth. Græc. xiii, 32); Conringii (Introduct.) and
Mangeti (Bibl. Med.) Pliny says of fire as a corrective of the state of
the atmosphere, “Est et ipsis ignibus medica vis. Pestilentiæ, quæ solis
obscuratione contrahitur, ignis suffitu multiformiter auxiliari, certum
est. Empedocles et Hippocrates id demonstravere diversis locis.” (H. N.
xxxvi, 69.) With the same intention Simeon Seth proposes fumigations
with frankincense. The historian Herodian relates that fumigations with
aromatics were recommended as a preventive of the plague. (i.)
Galen, in like manner, attributes the origin of epidemics to the state
of the atmosphere in a great measure, but also holds that the nature of
the country may contribute; as, for example, its vicinity to a gulf like
the Charonian, from which miasmata are exhaled that taint the air and
occasion diseases. In many passages of his ‘Commentary on the Epidemics’
of Hippocrates, he states that epidemical diseases arise from the
condition of the country in which they prevail. Lucretius accounts for
the prevalence of epidemical diseases upon similar principles:
“Atque ea vis omnis morborum, pestilitasque,
Aut extrinsicus, ut nubes nebulæque superne
Per cœlum veniunt, aut ipsâ sæpe coorta
_De terrâ surgunt_, ubi putrorem humida nacta est,
Intempestivis pluviisque, et solibus icta.”
(De Rerum Nat. vi, 1100.)
Silius Italicus appears to refer an epidemical fever to the same cause.
(xiv.)
In his work, on the ‘Varieties of Fever,’ Galen expresses his opinion
on this subject very fully. He remarks that an atmosphere of a hot
constitution, such as generally prevails at the time of the rising of
the dog-star, having been inhaled by the heart, increases the heat
in it, from which it is diffused all over the system, and enkindles
a febrile affection. In pestilential constitutions, he adds, it is
principally by the respiration that the disease is contracted, although
sometimes it may arise from the fluids of the body being disposed to
putrescency, which is increased by the condition of the atmosphere; but
for the most part epidemical complaints derive their origin from the
atmosphere being tainted with putrid exhalations. The putridity of the
atmosphere may be occasioned either by a multitude of dead bodies which
have not been burnt, as is apt to happen in wars, or it may arise from
the exhalations of certain marshes or lakes in the summer season, or
sometimes the inordinate heat of the atmosphere may give rise to them, as
happened in the case of the Athenian plague, according to the testimony
of Thucydides. And here we must digress to remark, that Homer evidently
ascribes the plague which attacked the Grecian army to the great heat of
the sun. See the Commentary of Eustathius on the beginning of the Iliad;
Ammianus Marcellinus (xix); Heraclides Ponticus (Allegor); and Macrobius
(Saturn. vii, 5.) Galen, however, inculcates that the constitution of the
atmosphere alone is not sufficient to produce disease without a peculiar
disposition of the body to admit it; for that, otherwise, all without
exception would be seized with the prevailing epidemic. This leads him
to give directions to correct the intemperament of the body when it is
such as disposes it to be readily affected by the constitution of the
atmosphere. His directions are similar to those of our author. Besides
the causes of epidemical diseases which we have mentioned, he states
that unwholesome food and drink may sometimes, though rarely, give rise
to them. Of this he relates a striking instance. (De Rebus boni et mali
Succi, c. i.) He remarks that the most common epidemical diseases are
pestilential fevers. We shall have occasion to state his opinion of them
in the next Section.
Of the Greek authors posterior to Galen, Oribasius and Aëtius give the
same account of epidemical diseases as our author; and the others either
do not treat of them at all, or class them with the subject of our next
Section.
Avenzoar has given us an elaborate treatise on epidemical complaints.
(iii.) The first cause of them which he mentions is a humid and warm
state of the atmosphere, such as that to which Hippocrates ascribed the
pestilence which afflicted Thasus in his time. (Epid. iii.) The other
causes enumerated by him are the effluvia from dead bodies, stagnant air,
the miasmata from stagnant and corrupted waters, and unwholesome food.
(iii, 3, 1.)
On the origin of epidemical diseases, especially the pestilence, see,
in particular, Haly Abbas (Theor. v, 11.) The principal causes of the
change of the atmosphere to a pestilential state, according to Haly, are
the nature of the country and the season of the year. The former cause
operates owing to the putrid effluvia arising from corrupted fruit,
pot-herbs, &c., or the miasmata from marshes, cloacæ, or dead bodies,
whether of men or cattle. It was from such causes, he remarks, that
the plague of Athens derived its origin. The nature of the season, as
it produces diseases in the vegetable, so does it also in the animal
creation. As epidemical complaints, he mentions ephemerals, cynanche,
smallpox, acute fevers, and other fatal diseases.
Avicenna’s account of the origin of pestilential and epidemic diseases
is taken almost entirely from Galen; he therefore enumerates as causes
of them, a humid and warm state of the atmosphere, the stagnant air of
caverns, the miasmata of lakes and marshes, and the effluvia from dead
bodies. (iv, i, 4.) Alsaharavius enumerates exactly the same causes.
(32.) Rhases’ account is mostly taken from Hippocrates and Galen.
(Contin. xxx.)
The historian Ammianus Marcellinus gives an ingenious disquisition on
the origin of these diseases; but the distinction which he endeavours to
establish in the following passage is not acknowledged by the medical
authors in general: “Prima species luis _Pandemus_ appellatur, quæ
efficit in aridioribus locis agentes caloribus crebris interpellari;
secunda, _Epidemus_ quæ tempore ingruens acies hebetat luminum, et
concitat periculosos humores; tertia, _Lœmodes_, quæ itidem temporaria
est, sed volucri velocitate letabilis.” (xix, 4.) The causes of these
complaints, as enumerated by him, are excessive heat, cold, drought, or
moisture, effluvia from putrid bodies, and exhalations from the earth.
According to Diodorus Siculus, the causes which gave rise to the
pestilential epidemic which attacked the Carthaginian army in Sicily were
the marshy nature of the country in which they were encamped, the bodies
of the dead lying unburied, and the excessive heat of the season. (xiv.)
He ascribes the plague of Athens to similar causes. (xii. 58.)