208 ANTHROPOLOGY. 
Tying of the common carotid, after Zang, pl. 189, 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; 7, common 
~earotid; *, internal jugular. 
5 es of the axillary artery in the left axilla, fig. 6a; A, B, cision exposing 
the artery: a, axillary artery; 6, external Gueuiele artery; h, external 
thoracic vein; 0, we nerve; p, median nerve; 4g, silage nerve. 
In the region of the incision, b 6, external thoracic artery ; c, subscapularis 
artery ; d, posterior circumflex scapular artery; e, anterior do.; h, external 
thoracic vein; 7, subclavian vein; k, posterior, J, anterior circumflex scapu- _ 
lar vein; m, brachial vein; n, ulnar vein; 7, 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 = surgical 
operations. 
The principal instrument required is the one ini: as the trepan or 
trephine, of which innumerable modifications have at different times been 
constructed. Zhe curved or brace trepan is shown in pl. 140, fig. 62. This 
consists of a handle part and two extremities. The handle, a, 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, 4, is of steel, 
three and a quarter inches long, and consisting of two equal ares; 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, & The 
cylindrical portion, 7, 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, h, in such a manner > 
that the cylinder cannot come off from the pin. The button, 2, 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 f, The lower arm, J, is like the upper, and at its anterior extremity is 
provided with a cylindrical tube, m, 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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