"A highly respectable lady of this city possesses the ability of developing sounds similar, both in character and degree, to those professedly elicited, by the Rochester impostors, from the Spirit world. We have witnessed the production of the sounds by the lady referred to, and have been permitted to examine the mechanism by which they are produced. Without entering at this time into a very minute anatomical and physiological explanation, it is sufficient to state that the muscles inserted into the upper and inner side of the large bone of the leg (the tibia), near the knee-joint, are brought into action so as to move the upper surface of the bone just named laterally upon the lower surface of the thigh bone (the femur), giving rise, in fact, to a partial lateral dislocation.[10] This is effected by an act of the will, without any obvious movement of the limb, occasioning a loud noise, and the return of the bone to its place is attended by a second sound. Most of the Rochester rappings are double. It is practicable, however, to produce a single sound by moving the bone out of place with the requisite quickness and force, and allowing it to slide slowly back, in which case it is noiseless. "The visible vibrations of articles in the room, situated near the operator, occur, if the limb, or any portion of the body, is in contact with them at the time the sounds are produced. The force of the semi-dislocation of the bone is sufficient to occasion distinct jarring of the doors, tables, etc., if in contact. The intensity of the sound may be varied in proportion to the force of the muscular contractions, and this will render the apparent source of the rappings more or less distinct. "We have witnessed repetitions of experiments, in the case just referred to, sufficient to exhibit to us all the phenomena of the sounds belonging to the Rochester rappings, and, without further explanations at this time, we append our names in testimony of the facts contained in the foregoing hastily penned exposition. "AUSTIN FLINT, M. D., } "CHARLES A. LEE, M. D., } University "C. B. COVENTRY, M. D., } of Buffalo. "February 17, 1851." [10] This article was also published in the Buffalo Medical Journal for March, 1851, with a note saying that the _editor_ had _taken the liberty_ to "correct an error in the account of the displacement of the joint which produces the sounds." That correction was of the sentence we have italicized, and the editorial correction reads as follows: