The Seerstone Test — Joseph Smith Sees Nothing When Martin Substitutes a False Stone

During the translation of the Book of Mormon, Martin Harris devised a test to prove Joseph Smith was genuinely reading from a divine instrument rather than reciting from memory. He related this remarkable story to Edward Stevenson, who recorded it in detail:

'Martin explained the translation as follows: By aid of the seerstone, sentences would appear and were read by the Prophet and written by Martin, and when finished he would say, "Written," and if correctly written, that sentence would disappear and another appear in its place, but if not written correctly it remained until corrected, so that the translation was just as it was engraven on the plates, precisely in the language then used.'

'While [throwing stones into the river for exercise], Martin found a stone very much resembling the one used for translation, and on resuming their labor of translation, Martin put in place the stone that he had found. He said that the Prophet remained silent, unusually and intently gazing in darkness, no traces of the usual sentences appearing. Much surprised, Joseph exclaimed, "Martin! What is the matter? All is as dark as Egypt!"'

Martin's reply: 'to stop the mouths of fools, who had told him that the Prophet had learned those sentences and was merely repeating them.' When the true stone was restored, translation resumed normally. The test proved conclusively to Martin that Joseph was not reciting from memory.

In other accounts, it is noted that after becoming weary from the work of translation, Martin and Joseph would go down to the river to exercise by throwing stones into the water, which provided the opportunity for Martin to find the look-alike stone. Additionally, Martin clarified that the seer stone differed significantly in appearance from the Urim and Thummim, which he described as two clear stones set in rims resembling spectacles, only larger. It is also mentioned that once the Prophet asked Martin why he had performed the test, Martin's 'countenance betrayed him' before he gave his explanation.

Fuller account of this event (as retold in Edward Stevenson, 'The Three Witnesses to the Book of Mormon,' The Latter-day Saints' Millennial Star 44, no. 6 (February 6, 1882): 86–87):

After continued translation they would become weary, and would go down to the river and exercise by throwing stones out on the river, etc. While so doing on one occasion, Martin found a stone very much resembling the one used for translating, and on resuming their labor of translation, Martin put in [its] place the stone that he had found. He said that the Prophet remained silent, unusually and intently gazing in darkness, no traces of the usual sentences appearing. Much surprised, Joseph exclaimed, "Martin! What is the matter? All is as dark as Egypt!" Martin's countenance betrayed him, and the Prophet asked Martin why he had done so. Martin said, to stop the mouths of fools, who had told him that the Prophet had learned those sentences and was merely repeating them, etc.