Commence at the second Cervical, the first spinous process below the occiput, and let the fingers glide smoothly downward over the tips or along the sides of the spinous processes, _without interruption of motion_, until they reach the Sacrum. The palpater notes each vertebra passed and its number--mentally--so that when he reaches the Sacrum he knows that he has passed every intervening vertebra and received a touch impression from each. The Sacrum itself may usually be recognized by its peculiar shape and also by its articulations with the ilia. If the fingers are raised from their contact during the count, the palpater must recommence at the second Cervical. It is impossible to be accurate in replacing the hand, once removed, until the count has been established and the peculiarities of certain vertebrae remembered, together with their numbers. To determine the location of the fourth Lumbar where, on account of obesity, lipoma, Cervical lordosis, etc., the count of Cervicals or Sacral palpation is difficult, drop on heels behind the patient and place the second finger of each hand on the crest of the ileum. Then let the thumbs meet in the mid-spinal line in the same horizontal plane as the two second fingers, which spot should correspond to the interspace between third and fourth Lumbars. This measurement is accurate in about 98% of all cases, when patient sits erect; when it varies it will vary by about half the width of a Lumbar spinous process. The count should be repeated until the palpater is certain that he is able to palpate every spinous process distinctly or to locate accurately any impalpable one. In making the count, palpater may note the number of some very prominent and easily recognizable Dorsal or Lumbar vertebra to be referred to as a starting point for a recount if confusion arises later. This recounting from some prominent vertebra is permissible only after the first accurate count has been made, but then will save the full count, especially when the patient is in an unfavorable position, as lying on table during adjustment. Difficulties in Counting The commonest difficulties met with in counting are the following: Inaccessibility of third Cervical, which lies closely beneath the spinous process of the second and, unless unusually large or somewhat out of its proper position, cannot be readily felt. An occasional anterior fourth or fifth Cervical which may escape notice unless the head is flexed far toward or the transverse processes examined. Lipoma or other adipose tissue covering part of the spine. A missing epiphyseal plate resulting from fracture and absorption, which absence may simulate a wide interspace and be overlooked without careful and detailed observation.