The deep position of the kidneys makes them usually inaccessible to physical exploration to any practical extent. In stout persons they are so entirely covered by their own immediate envelope of fat, by the adipose tissue of the mesentery, and by the thick abdominal walls as to be completely indistinguishable. In thinner persons deep palpation with both hands may enable us to say that there is a diminished resistance to pressure, as in the case of movable kidney, or that there is or is not any decided enlargement. Slighter changes in size cannot be accurately determined, although Bartels[1] states that he was once enabled to detect a considerable enlargement in a case of parenchymatous nephritis by double palpation. In moderately thin persons the lower end of the kidney can be more or less distinctly felt. [Footnote 1: _Ziemssen_, vol. xv.] A position upon the hands and knees (not the gynecological semi-prone position), allowing the whole abdomen to gravitate directly away from the backbone, is said to afford, by the varying concavity of the lumbar region on the two sides, information as to the absence of either kidney from its usual place. When the kidney, however, is displaced, and when it comes decidedly forward from increase in its own size or from the pressure of a tumor behind it, it may very often become extremely accessible. Percussion gives even less information than palpation, since the dulness of the lumbar muscles extends laterally beyond that of the kidneys, and is of itself so complete as to offer no change from the addition or subtraction of the resistance of the underlying organ.[2] [Footnote 2: It is probable that Simon's method of thrusting the hand into the rectum and large intestine might be made available by a person with a small hand and arm for diagnosis in doubtful cases where the value of the information to be obtained would be sufficient to compensate for the risk of serious injury. The removal of the kidneys may be accomplished through the rectum--and has been effected many times by myself and assistants--in cases where a complete autopsy is refused. The manoeuvre is not very difficult through a large and especially a female pelvis, but under other circumstances may be somewhat fatiguing. Considerable post-mortem information in regard to other organs may be obtained in the same way.]