16. Therefore the air is of an equal temper in all places, but winter is not in all places alike nor equally cold; but some parts of the habitable world are cold and moist, others hot and dry, not by chance, but because there is but one substance of heat and dryness. For the greatest part of Africa is hot and without water. But they that have travelled Scythia, Thrace, and the Pontic regions report them to be full of vast lakes, and large and deep rivers. And as for those regions lying between, those parts that join upon lakes and marshes are most cold by reason of the exhalations from the water. Posidonius therefore, affirming the freshness and moistness of the air of marshes to be the cause of its cold, has no way disturbed the probability of our argument, but rather added to the strength of it; for the air would not always be the colder the fresher it is, unless cold has its original from moisture. And therefore Homer much more truly shows us the fountain of cold, when he says, Chill from the river blows the wind Before the coming morn.[122] Then again it many times happens that our sense deceives us. So that when we feel cold garments or cold wool, we believe we feel them to be moist, by reason of the substance which is common to both, and of their natures which are coherent and familiar one with another. But in climates where the cold is extreme, it oftentimes breaks and cracks both pots and vessels, whether made of earth or brass,—none empty, but all full, the cold giving force and might to the liquor within,—which made Theophrastus say, that the air breaks those vessels, making use of the cold as of a hammer; whether more eloquently or more truly spoken, I leave you to judge. For then vessels full of pitch or milk should be more subject to be broken by the air. But water seems to be cold of itself, and that primitively too; for in respect of the coldness of it, it is opposite to the heat of the fire; as to drought in respect of its moisture, and to ponderosity in regard of its lightness. Lastly, fire is altogether of a dissipating and dividing nature; water, of a nature to fasten and contain, holding and joining together by virtue of its moisture. Which was the reason why Empedocles called fire “a pernicious contention,” but water a “tenacious friendship.” For the nourishment of fire is that which changes into fire, and it changes that which is as it were of kin and familiar to it. What is contrary to it, as water, cannot be changed by it, or at least only with great difficulty. True it is, that as for itself, as I may so say, it cannot be burned; but as for green wood and wet straw, it overcomes them with much struggling, while the heat and cold contending together, by reason of their moisture and their natural antipathy, produce only a dull flame, clouded with smoke, that makes little progress upon the materials.