Job 37:17

How thy garments are warm - What are warmth and cold? How difficult this question! Is heat incontestably a substance, and is cold none? I am afraid we are in the dark on both these subjects. The existence of caloric, as a substance, is supposed to be demonstrated. Much, satisfactorily, has been said on this subject; but is it yet beyond doubt? I fear not. But supposing this question to be set at rest, is it demonstrated that cold is only a quality, the mere absence of heat? If it be demonstrated that there is such a substance as caloric, is it equally certain that there is no such substance as frigoric? But how do our garments keep us warm? By preventing the too great dissipation of the natural heat. And why is it that certain substances, worked into clothing, keep us warmer than others? Because they are bad conductors of caloric. Some substances conduct off the caloric or natural heat from the body; others do not conduct it at all, or imperfectly; hence those keep us warmest which, being bad conductors of caloric, do not permit the natural heat to be thrown off. In these things we know but little, after endless cares, anxieties, and experiments!

But is the question yet satisfactorily answered, why the north wind brings cold, and the south wind heat? If it be so to my readers, it is not so to me; yet I know the reasons which are alleged.

How thy garments are warm - What is the reason that the garments which we wear produce warmth? This, it would seem, was one of the philosophical questions which were asked at that time, and which it was difficult to explain. Perhaps it has never occurred to most persons to ask this apparently simple question, and if the inquiry were proposed to them, plain as it seems to be, they would find it as difficult to give an answer as Elihu supposed it would be for Job. Of the fact here referred to that the garments became oppressive when a sultry wind came from the south, there could be no dispute. But what was the precise difficulty in explaining the fact, is not so clear. Some suppose that Elihu asks this question sarcastically, as meaning that Job could not explain the simplest matters and the plainest facts; but there is every reason to think that the question was proposed with entire seriousness, and that it was supposed to involve real difficulty. It seems probable that the difficulty was not so much to explain why the garments should become oppressive in a burning or sultry atmosphere, as to show how the heated air itself was produced It was difficult to explain why cold came out of the north Job 37:9; how the clouds were suspended, and the lightnings caused Job 37:11, Job 37:15-16; and it was not less difficult to show what produced uncomfortable heat when the storms from the north were allayed; when the earth became quiet, and when the breezes blowed from the south. This would be a fair question for investigation, and we may readily suppose that the causes then were not fully known.

When he quieteth the earth - When the piercing blast from the north dies away, and the wind comes round to the south, producing a more gentle, but a sultry air. It was true not only that the whirlwind came from the south Job 37:9, but also that the heated burning air came also from that quarter, Luke 12:55. We know the reason to be that the equatorial regions are warmer than those at the north, and especially that in the regions where Job 54ed the air becomes heated by passing over extended plains of sand, but there is no reason to suppose that this was fully understood at the time referred to here.

37:17 Quieteth - The air about the earth. From the south - By the sun's coming into the southern parts, which makes the air quiet and warm.