Whoever wishes to investigate medicine properly, should proceed thus--

• First consider the seasons of the year, and the effects each of them produces; they are not at all alike, but one spring can differ as much from another as summer differs from autumn.

• Then the winds -- both hot and cold; those common to all countries, as well as those peculiar to each locality.

• Consider the qualities of the waters, for as they differ from one another in taste and weight, so also do they differ much in their qualities.

• In the same manner, when one comes into a city to which he is a stranger, he ought to consider its situation, how [the city] lies as to the winds and the rising of the sun; for its influence is not the same whether it lies to the north or the south, to the rising or to the setting sun.

• ...the waters which the inhabitants use -- are they marshy and soft, or hard and running from elevated and rocky situations; are they saltish and unfit for cooking;

• the ground -- is it bare and dry, or wooded and well-watered; does it lie in a hollow and is it hot, or is it elevated and cold; and

• the mode in which the inhabitants live -- what are their pursuits? are they fond of drinking and eating to excess, and given to indolence? or are they fond of exercise and labor, and moderate in eating and drinking?

And in particular, as the season and the year advances, he can tell what epidemic diseases [diseases that are not always present in the population] will attack the city, either in summer or in winter, and what each individual will be in danger of experiencing from the change in routine.

And respecting the seasons, one may judge whether the year will prove sickly or healthy from the following observations--

• If the appearances connected with the rising and setting stars be as they should be; if there be rains in autumn; if the winter be mild, neither very tepid nor unseasonably cold, and if in spring the rains be seasonable, and so also in summer, the year is likely to prove healthy.

• If the winter be dry and northerly, and the spring showery and southerly, the summer will necessarily be of a febrile character, and give rise to eye infections and dysenteries.  For when suffocating heat sets in all of a sudden, while the earth is moistened by the vernal [springtime] showers, and by the south wind, the heat is necessarily doubled from the earth, which is thus soaked by rain and heated by a burning sun, while, at the same time, men's bellies are not in an orderly state, nor the brain properly dried; for it is impossible, after such a spring, but that the body and its flesh must be loaded with humors, so that very acute fevers will attack all, but especially those of a phlegmatic [sluggish; dull; apathetic] constitution.  Dysenteries are also likely to occur to women and those of a very humid temperament.

• If at the rising of the Dog Star rain and wintery storms occur and the Etesian winds blow [Mediterranean winds that blow from the north for several weeks during the summer], there is hope that these diseases will cease, and that the autumn will be healthy.  Otherwise, it is likely to be a fatal season to children and women, and least of all to old men; and that convalescents will pass into quartans [fevers were named according to their period of cyclical recurrence; a quartan fever is one that recurs every every fourth day counting the first day of onset as day one], and from quartans into dropsies [edema]

• If the winter be southerly, rainy and mild, and the spring northerly, dry, and wintry, then women with child whose delivery is due by spring are apt to miscarry; and if they do bring forth, have feeble and sickly children, so that they either die presently or are tender, feeble, and sickly, if they live.  Such is the fate of the women.

The others are subject to dysentery and dry ophthalmia [eye inflammation], and some have catarrh [heavy flow of mucus] beginning in the head and descending to the lungs.  Men of a phlegmatic temperament are likely to have dysenteries; and women, also, from the humidity of their nature, the phlegm descending downwards from the brain; those who are bilious [bad-tempered], too, have dry ophthalmies from the heat and dryness of their flesh; the aged, too, have catarrhs from their flabbiness and wasting away of the veins, so that some of them die suddenly and some become paralytic on the right side or the left [stroke].

For when, the winter being southerly and the body hot, the blood and veins are not properly constringed [contracted, constrained]; a spring that is northerly, dry, and cold, having come on, the brain when it should have been relaxed and purged, by nasal congestion and hoarseness is then constringed and contracted, so that the summer and the heat occurring suddenly, and a change supervening, these diseases occur.  And such cities as lie well to the sun and winds, and use good waters, are less affected by these changes, but those that use marshy and pooly waters, and lie well both as regards the winds and the sun, these all feel it more.

• If the summer be dry, those diseases soon cease, but if rainy, they are protracted.  Sores are apt to fester from the slightest cause.  Lienteries [failure to digest food before eliminating it] and dropsies supervene at the conclusion of diseases since the bowels do not readily dry up.

• If the summer and autumn be rainy and southerly, the winter must be sickly.  Ardent fevers are likely to attack the phlegmatic and men over forty; pleurisy and pneumonia attack those that are bilious.

• If the summer is dry and northerly, but the autumn rainy and southerly, headache and mortifications of the brain are likely to occur; and in addition hoarseness, nasal congestion, coughs, and in some cases, consumption.

• But if the season is northerly and without water, there being no rain, either during the Dog Star or at Arcturus [August through mid-September], it is beneficial to those who are naturally phlegmatic and those who are of a humid temperament, and with women; but it is most harmful to the bilious; for they become much parched up, and are attacked by dry ophthalmia, fevers both acute and chronic, and in some cases melancholy.  For the most humid and watery part of the bile is dried up leaving the thickest and most acrid portion, and similarly with the blood.  Consequently these diseases come upon them.  But all these are beneficial to the phlegmatic, for they are thereby dried up, and reach winter not oppressed with humors.

Now, the greatest and most dangerous are the two solstices, and especially the summer, and also the two equinoxes, but especially the autumnal.  One ought also to be guarded about the rising of the stars, especially of the Dog Star, then of Arcturus, and then the setting of the Pleiades; for diseases are especially apt to prove critical in those days, and some prove fatal, some pass off, and all others change to another form and another constitution.