All men have heard of the Mormon Bible, but few except the "elect" have seen it, or, at least, taken the trouble to read it. I brought away a copy from Salt Lake. The book is a curiosity to me, it is such a pretentious affair, and yet so "slow," so sleepy; such an insipid mess of inspiration. It is chloroform in print. If Joseph Smith composed this book, the act was a miracle — keeping awake while he did it was, at any rate. If he, according to tradition, merely translated it from certain ancient and mysteriously-engraved plates of copper, which he declares he found under a stone in an out-of-the-way locality, the work of translating was equally a miracle, for the same reason.

On the Book of Mormon, Roughing It (published 1872), pp. 58-59. - Roughing It (1872)