THE MUMMIES. -- The editor of the Reveille, in one of his letters from the Upper Mississippi, gives the following account of his interviews with Joe Smith's mother, who keeps the Mummies at Nauvoo.

"Her story in regard to the mummies, (learned from Joe,) is about as follows: It seems that, for the express purpose of corroborating the "brass plates" which were one day to be dug up and translated as "the Book of Mormon," the angel of the Lord, three thousand years ago, appeared to Joseph in Egypt and delivered to him a wooden case, containing a roll of papyrus, which was to be buried by him with the family of one of the patriarchs; that Joseph did so, depositing the case on the Queen's breast, where it lay until the discovery of the "brass plates," the Lord then causing the bodies to be discovered also and conveyed with the identical deposit of Joseph into the hands of "Joe." Joe 'never had six month's schoolin' in his born days," but as soon as "the gift was gin' him," he could "translate any thing;" accordingly, having already deciphered the plates, he made short work of the hieroglyphics, and his interpretation which, while it fully proves the Book of Mormon, would enlighten even unto amazement, the Champollions of the Bibliotheque du Roi and the British Museum! Of all the bare-faced jargon that ever was uttered, the grave relation of the poor old woman was the most ridiculous; and while her pitiable conviction of its entire truth really gladdened the heart, it would be impossible to repress one's regret that the impudent impostor had left the world, without at least one especial good kicking for having so deceived his own mother. Not a circle, serpent, altar, ibis, or any of the familiar and now understood idiographic character of the Egyptian, but this shrewd yet ignorant knave had given his own interpretation to, and so committed the latter to his followers, not only braving but confidently defying inevitable exposure. The whole thing is too gross to bear patiently, too painful to laugh at; somehow or other the delusion of this bent and white headed old creature has more in it to disgust one with the memory of Smith than all his other humbug and even crime.