Page:A Treatise on Painting.djvu/225

 mountains, and breaking and recoiling with redoubled force, like waves against a rocky shore. The air should be rendered awfully dark, by the mist, dust, and thick clouds.   , let the air exhibit a confused mixture of smoke, arising from the discharge of artillery and musquetry, and the dust raised by the horses of the combatants; and observe, that dust being of an earthy nature, is heavy; but yet, by reason of its minute particles, it is easily impelled upwards, and mixes with the air; nevertheless, it naturally falls downwards again, the most subtle parts of it alone gaining any considerable degree of elevation, and at its utmost height it is so thin and transparent, as to appear nearly of the colour of the air. The smoke, thus mixing with the dusty air, forms a kind of dark cloud, at the top of which it is distinguished from the dust by a blueish cast, the dust retaining more of its natural colour. On that part from which the light proceeds, this mixture of air, smoke, and dust, will appear much brighter than on the opposite side. The more the combatants are involved in this turbulent mist, the less distinctly they will be seen, and the more confused will they be in their lights and shades. Let the faces of the musketeers, their bodies, and every object near them, be tinged with a reddish hue, even the air or cloud of dust; in short, all that surrounds them. This red tinge you will diminish, in proportion to their distance, Rh