.208 ANTHROPOLOGY. 



Tying of the common carotid^ after Zang, 73?. 139, fig. 5 ; A, B, incision 

 laying bare the carotid artery : \ sternal, ^, clavicular portions of the 

 sterno-cleido-mastoid muscle ; ', omo-hyoid muscle ; *, rectus capitis anticus 

 major muscle ; ^, portion of the thyroid gland ; *, sheath surrounding the 

 'carotid artery and internal jugular vein, a portion of it removed ; ', common 

 carotid; ', internal jugular. 



Tying of the axillary artery in the left axilla^ fig. Qa; A, B, incision exposing 

 the artery : a, axillary artery ; i, external thoracic artery ; A, external 

 thoracic vein; 0, musculo-cutaneous nerve; p, median nerve; §■, ulnarnerve. 

 In the region of the incision, h i, external thoracic artery ; c, subscapularis 

 artery ; c7, posterior circumflex scapular artery ; e, anterior do. ; A, external 

 thoracic vein ; e", subclavian vein ; k^ posterior, /, anterior circumflex scapu- 

 lar vein ; ???, brachial vein ; 91, ulnar vein ; ?•, median cutaneous nerve of 

 the arm. 



Tying of the brachial artery in the middle of the arm^ fig, 6 6, A, B, incision : 

 *, musculo-cutaneous nerve ; ', median nerve ; ', brachial artery ; *, radial 

 nerve ; ^, brachial vein. 



4. Trepanning. 



The penetration of the cavity of the cranium by sawing out a circular 

 poition of its walls (trepanatio cranii) belongs to the earliest surgical 

 operations. 



The principal instrument required is the one known as the trepan or 

 trephine, of which innumerable modifications have at different times been 

 constructed. T'he curved or brace trepan is shown in |;?. 140, fig. 62. This 

 consists of a handle part and two extremities. The handle, o, is a cylindrical 

 steel rod, about four inches long, and surrounded by ebony three quarters 

 of an inch thick in the middle, tapering towards the ends, and attached 

 nearly at a right angle to the two arms. The upper arm, i, is of steel, 

 three and a quarter inches long, and consisting of two equal arcs ; at its 

 anterior extremity is the perpendicular steel portion, c, one inch long and 

 five lines thick, thickened and blunt below, and turned off above so as to 

 present a cylindrical pin an inch and a half long, ending with a short four- 

 sided female screw, and when in use connected with the head, h. The 

 cylindrical portion, f of the head is twenty lines long, strongest superiorly, 

 with a screw collar above of three lines in length, and pierced by a cylin 

 drical canal which fits over the pin, d. The superior portion of the canal 

 receives the disk, g^ which, with its quadrangular hole, is placed over the 

 female screw of the pin, d, and fastened by the screw, A, in such a manner 

 that the cylinder cannot come off from the pin. The button, ?,", is a circular 

 disk, two inches broad, rounded off on both sides, having in its inferior sur- 

 face a screw cavity which fits over the male screw out on the upper end 

 of / The lower arm, ?, is like the upper, and at its anterior extremity is 

 provided with a cylindrical tube, w, seventeen lines long, and six broad. 

 This, at its lower end, has a four-cornered cavity, n, for the reception of 

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