_prophecies_ that referred to events _anterior_ to his time? In what light, or on what principle, shall we most correctly read the prophetic drama of creation? In the light, I reply, of scientific discovery,--on the principle that the clear and certain must be accepted, when attainable, as the proper exponents of the doubtful and obscure. What fully developed history is to the prophecy which of old looked forwards, fully developed science is to the prophecy which of old looked backwards. Scarce any one will question whether that portion of the creation drama which deals with the heavenly bodies ought to be read in the light of established astronomic discovery or no; for, save by perhaps a few of Father Cullen's monks, who can still hold that the sun moves round the earth, and is only six feet in diameter, all theologians have now received the astronomic doctrines, and know that they rest upon a basis at least as certain as any of the historic events symbolized in fulfilled prophecy. And were we to challenge for the established geologic doctrines a similar place and position with respect to those portions of the drama which deal with the two great kingdoms of nature, plant and animal, we might safely do so in the belief that the claim will be one day as universally recognized as the astronomic one is now. On this principle there may, of course, be portions of the _prophetic_ pre-Adamic past of as doubtful interpretation at the present time, from the imperfect development of physical science, as is any portion of the prophetic future from the imperfect development of historic events. The science necessary to the interpretation of the one may be as certainly still to discover as the events necessary to the interpretation of the other may be still to take place. Three centuries have not yet passed since astronomic science was sufficiently developed to form a true key to the various notices of the heavenly bodies which occur in Scripture; among the others, to the notice of their final appearance on the _fourth_ day of creation. Little more than half a century has yet passed since geologic science was sufficiently developed to influence the interpretation given of the three _other_ days' work. And respecting the work of at least the first and second days, more especially that of the second, we can still but vaguely guess. The science necessary to the right understanding of these portions of the prophetic record has still, it would seem, to be developed, if, indeed, it be destined at all to exist; and at present we can indulge in but doubtful surmises regarding them. What may be termed the three _geologic_ days,--the third, fifth, and sixth,--may be held to have extended over those Carboniferous periods during which the great plants were created,--over those Oolitic and Cretacious periods during which the great sea monsters and birds were created,--and over those Tertiary periods during which the great terrestrial mammals were created.