Depart from evil is understanding. ] Depart from the evil within thee, and the evil without thee; for thy own evil, and the evil that is now, through thee, brought into the world, will conspire together to sink thee into ruin and destruction. Therefore, let it be thy constant employment to shun and avoid that evil which is everywhere diffused through the whole moral world by thy offense; and labour to be reconciled to him by the righteousness and true holiness, that thou mayest escape the bitter pains of an eternal death. See the note on ver. 12. FROM what has been observed on verses 25, 26, and from the doctrine of the atmosphere in general, I can safely draw the following conclusions: - 1. From the gravity and elasticity of the air, we learn that it closely invests the earth, and all bodies upon it, and binds them down with a force equal to 2160 pounds on every square foot. Hence it may properly be termed the belt or girdle of the globe. 2. It prevents the arterial system of animals and plants from being too much distended by the impetus of the circulating juices, or by the elastic power of the air so plenteously contained in the blood, and in the different vessels both of plants and animals. 3. By its gravity it prevents the blood and juices from oozing through the pores of the vessels in which they are contained; which, were it not for this circumstance, would infallibly take place. Persons who ascend high mountains, through want of a sufficiency of pressure in the atmosphere, become relaxed, and spit blood. Animals, under an exhausted receiver, swell, vomit, and discharge their faeces. 4. It promotes the mixture of contiguous fluids; for when the air is extracted from certain mixtures, a separation takes place, by which their properties, when in combination, are essentially changed. 5.

To this principle we owe winds in general, so essential to navigation, and so necessary to the purification of the atmosphere. The air is put into motion by any alteration of its equilibrium. 6. Vegetation depends entirely gravity and elasticity of the air. Various experiments amply prove that plants in vacuo never grow. 7. Without air there could be no evaporation from the sea and rivers; and, consequently, no rain; nor could the clouds be suspended, so necessary to accumulate and preserve, and afterwards to distil, these vapours, in the form of dew, rain, snow, and hail, upon the earth. 8. Without air, all the charms of vocal and instrumental sounds would become extinct; and even language itself would cease. 9. Without it heat could not be evolved, nor could fire exist; hence a universal rigour would invest the whole compass of created nature. 10. Without air, animal life could never have had a being; hence God created the firmament or atmosphere before any animal was produced. And without its continual influence animal life cannot be preserved; for it would require only a few moments of a total privation of the benefits of the atmosphere to destroy every living creature under the whole heaven. 11. It has been found, by repeated experiments, that a column or rod of quicksilver, about twenty-nine inches and a half high, and one inch in diameter, weighs about fifteen pounds; and such a column is suspended in an exhausted tube by the weight of the atmosphere; hence it necessarily follows, that a column of air, one square inch in diameter, and as high as the atmosphere, weighs about fifteen pounds at a medium. Thus it is evident that the atmosphere presses with the weight of fifteen pounds on every square inch; and, as a square foot contains one hundred and forty-four square inches, every such foot must sustain a weight of incumbent atmospheric air equal to two thousand one hundred and sixty pounds, as has been before stated. And from this it will follow, that a middle- sized man, whose surface is about fifteen square feet, constantly sustains a load of air equal to thirty-two thousand four hundred pounds! But this is so completely counterbalanced by the air pressing equally in all directions, and by the elasticity of the air included in the various cavities of the body, that no person in a pure and healthy state of the atmosphere feels any inconvenience from it; so accurately has God fitted the weight to the winds. It has been suggested that my computation of 15 square feet for the surface of a middle-sized man, is too much; I will, therefore, take it at 14 square feet. From this computation, which is within the measure, it is evident that every such person sustains a weight of air equal, at a medium, to about 30,240 lbs. troy, or 24,882 1/2 lbs. avoirdupois, which make 1, 777 stone, 4 lbs. equal to eleven TONS, two HUNDRED and eighteen pounds and a half. 12.

Though it may appear more curious than useful, yet from the simple fact which I have completely demonstrated myself by experiment, that the atmosphere presses with the weight or fifteen pounds on every square inch, we can tell the quantum of pressure on the whole globe, and weigh the whole atmosphere to a pound! The polar and equatorial circumference of the earth is well known. Without, therefore, entering too much into detail, I may state that the surface of the terraqueous globe is known to contain about five thousand, five hundred, and seventy-five BILLIONS of square FEET; hence, allowing fifteen pounds to each square inch, and two thousand one hundred and sixty pounds to each square foot, the whole surface must sustain a pressure from the atmosphere equal to twelve TRILLIONS and forty-two thousand billions of POUNDS! or six thousand and twenty-one BILLIONS of TONS! And this weight is the weight of the whole atmosphere from its contact with every part of the earth's surface to its utmost highest extent! Experiments also prove that the air presses equally in all directions, whether upwards, downwards, or laterally; hence the earth is not incommoded with this enormous weight, because its zenith and nadir, north and south pressure, being perfectly equal, counterbalance each other! This is also the case with respect to the human body, and to all bodies on the earth's surface. To make the foregoing calculations more satisfactory, it may be necessary to add the following observations: - A bulk of atmospheric air, equal to one quart, when taken near the level of the sea, at a temperature of 50 ø Fahrenheit, weighs about 16 grains, and the same bulk of rain water, taken at the same temperature, weighs about 14, 621 grains: hence rain water is about 914 times specifically heavier than air. I have already shown that the pressure of the atmosphere is equal to about 15 lbs. troy on every square inch; and that this pressure is the same in all directions; and thence shown that on this datum the whole weight of the atmosphere may be computed. I shall re-state this from a computation of the earth's surface in square miles, which is recommended to me as peculiarly accurate. A square mile contains 27, 878,400 square feet. The earth's surface, in round numbers, is 200,000,000, or two hundred millions, of square miles. Now, as from the preceding data it appears that there is a pressure of 19, 440 lbs. troy on every square yard, the pressure or weight of the whole atmosphere, circumfused round the whole surface of the earth, amounts to 12,043,468,800,000,000,000, or, twelve TRILLIONS. forty-three thousand four hundred and sixty-eight BILLIONS, eight hundred thousand MILLIONS of pounds. Though we cannot tell to what height the atmosphere extends, the air growing more and more rare as we ascend in it; yet we can ascertain, as above, the quantum of weight in the whole of this atmosphere, which the terraqueous globe sustains equally diffused over its surface, as well as over the surfaces of all bodies existing on it. At first view, however, it is difficult for minds not exercised in matters of philosophy to conceive how such an immense pressure can be borne by animal beings. Though this has been already explained, let the reader farther consider that, as fishes are surrounded by water, and live and move in it, which is a much denser medium than our atmosphere; so all human beings and all other animals are surrounded by air, and live and move in it.

A fish taken out of the water will die in a very short time: a human being, or any other animal, taken out of the air, or put in a place whence the air is extracted, will die in a much shorter time. Water gravitates towards the center of the earth, and so does air. Hence, as a fish is pressed on every side by that fluid, so are all animals on the earth's surface by atmospheric air. And the pressure in both cases, on a given surface, is as has been stated above; the air contained in the vessels and cells of animal bodies being a sufficient counterpoise to the air without. Having said thus much on the pressure of the atmosphere, as intimated by Job, the reader will permit me to make the following general reflections on the subject, of which he may make what use he may judge best. It is generally supposed that former times were full of barbaric ignorance; and that the system of philosophy which is at present in repute, and is established by experiments, is quite a modern discovery. But nothing can be more false than this; as the Bible plainly discovers to an attentive reader that the doctrine of statics, the circulation of the blood, the rotundity of the earth, the motions of the celestial bodies, the process of generation, &c., were all known long before Pythagoras, Archimedes, Copernicus, or Newton were born. It is very reasonable to suppose that God implanted the first principles of every science in the mind of his first creature; that Adam taught them to his posterity, and that tradition continued them for many generations with their proper improvements. But many of them were lost in consequence of wars, captivities, &c. Latter ages have re-discovered many of them, principally by the direct or indirect aid of the Holy Scriptures; and others of them continue hidden, notwithstanding the accurate and persevering researches of the moderns.

Matthew Henry Commentary

Original Hebrew