Every doctor who intends dedicating himself to the practice of this operation has to begin by the most accurate study of the elective points for puncturing according to the various affections; he should also know to what depth precisely to drive the needles in each case, in order to reach the site of the morbific principle and procure convenient exit for it; he ought to know equally well how long to leave the needle in the affected part, so as to obtain the best possible therapeutic results in each case. The points of election for carrying out puncturing in various maladies are spread over the whole superficies of the body, and amount in number to 388. Each of these is known by a special name. Each site of election stands in determinate relations, as to distance, to the known anatomical points, and may, therefore, be easily and precisely found by appropriate measurement. The unity of length for these measurements is called _tsun_, and is divided into ten _fen_; its value varies, however, according to whether the said measurements be taken on the head, the trunk, or the extremities. For the head, the length of the _tsun_ is calculated as equal to the distance existing between the inner and the outer angle of the eye; for the trunk, it is equivalent to the eighth part of the horizontal line between the two breast nipples; and for the extremities, it is equal to the length of the second phalanx of the middle finger, measured with the joints bent. There are twenty-six points of election upon which to carry out puncturing used as a remedy against toothache. There are also six other points of election for pains in the gums. One would naturally be disposed to believe that these points of election would be situated in proximity to the teeth. Instead, many of them are situated in distant parts of the body—for example, in the elbow, in the hands, the feet, the vertebral region, the coccyx, and so on. However, about half of them are to be found in the labial, maxillary, and periauricular regions. The puncturing of every point of election is almost always indicated for the cure of not only one but several, and, indeed, very often many, maladies; for example, the puncture carried out on the point of election, _kin-tche_, situated at the outer extremity of the bend of the elbow, may be utilized in more than twenty-five morbid conditions; among which are pains in the arm, paralysis of the arm, edema of the whole body, excessive perspiring, vomiting, hematemesis, toothache, boils, gastralgia, hemiplegia, and even cholera! This mode of cure depends on the special relation of each point of election to the so-called canals of transmission and communication (named in Chinese _king_) through which the blood and the vital spirits circulate, and which serve at the same time to transmit the “innate heat” and “the radical moisture” to all parts of the body. And here we must be allowed a brief digression in explanation of what we have just said.