lightning; or the lighting up of the clouds by the winds, produces this luminous appearance; or the mutual pressure of the clouds, or that of the wind against them, disengages the lightning. Or, one might say, that the interception of the light diffused from the stars, arrested for a time in the bosom of the clouds, is driven from them subsequently by their own movements, and by those of the winds, and so escapes from their sides; that the lightning is an extremely subtile light that evaporates from the clouds; that the clouds which carry the thunder are collected masses of fire; that the lightning arises from the motion of the fire, or from the conflagration of the wind, in consequence of the rapidity and continuousness of its motion. One may also attribute the luminous appearance of lightning to the rupture of the clouds under the action of the winds, or to the fall of inflammable atoms. Lastly, one may easily find a number of other explanations, if one applies to sensible facts, in order to search out the analogies which they present to the heavenly phænomena.
“Lightning precedes thunder, either because it is produced at the same moment that the wind falls on the cloud, while the noise is only heard at the instant when the wind has penetrated into the bosom of the cloud; or, perhaps, the two phænomena being simultaneous, the lightning arrives among us more rapidly than the noise of the thunder-bolt, as is in fact remarked in other cases when we see at a distance the clash of two objects.
“The thunderbolt may be produced either by a violent condensation of the winds, or by their rapid motion and conflagration. It may arise from the fact of the winds meeting in places which are too dense, in consequence of the accumulation of clouds, and then a portion of the current detaches itself and proceeds towards the lower situations; or else it may be caused by the fire which is contained in the bosom of the clouds precipitating