We learn, from the scientific facts which we have been discussing, a few of the secrets of natural magic. In their relations to heat, every flower, which adds to the adornment of the wilds of nature or the carefully-tended garden of the florist, possesses a power peculiar to itself; “Naiad-like lily of the vale,” and, “---- The pied wind-flowers, and the tulip tall, And narcissi, the fairest among them all,” are, by their different colours, prevented from ever having the same temperatures under the same sunshine. Every plant bears within itself the measure of the heat which is necessary for its well-being, and is endued with functions which mutely determine the relative amount of dew which shall wet its coloured leaves. Some of the terrestrial phenomena of this remarkable principle will still further illustrate the title of this volume. To commence with the most familiar illustrations, let us consider the consequences of change of temperature. However slight the additional heat may be to which a body is subjected, it expands under its influence; consequently, every atom which goes to form the mass of the earth moves under the excitation, and the first heat ray of the morning which touches the earth’s surface, sets up a vibration which is continued as a tremor to its very centre. The differences between the temperature of day and night are considerable; therefore all bodies expand under the influence of the higher, and contract under that of the lower temperature. During the day, any cloud obscuring the sun produces, in every solid, fluid, or aëriform body, within the range of solar influence, a check: the particles which had been expanding under the force of heat suddenly contract. Thus there must of necessity be, during the hours of sunshine, a tendency in all bodies to dilate, and during the hours of night they must be resuming their original conditions.