over the torrid, the temperate, and the frigid zones, it is plain that some would acquire the requisite conditions sooner than others, and that some might be so unfavourably situated as never to acquire them. The planets may be compared to such islands. They occupy, like the islands, different zones of temperature, and they are not in equally favourable circumstances. Neptune occupying the frigid, and Vulcan the torrid zone, are probably in much less favourable circumstances than the earth, occupying the temperate regions of the solar system; and, possibly, the circumstances are so unfavourable that the requisite conditions can never be acquired. Some may have been more favourably circumstanced than the earth, and their period of life may have preceded that of the earth, while others are only approaching the life conditions. It ought, however, to be kept in view, that there is no analogy that would lead us to infer that the conditions of life, and life itself, are so related that the former may be regarded as the ^cause of the latter, or that, by a physical law, the conditions of life necessarily develop living organisations. All the evidence afforded by the history of our globe points in a very different direction. It unmistakeably indicates a creative hand. Life, no doubt, demands certain physical conditions; but these conditions have no tendency to produce life. Light is a necessary condition to seeing, but there is no tendency in light to produce a living eye. When we
