PRACTICAL EXERCISES 177 



instruments for dissection one or two pairs of artery-forceps, a pair 

 of artery-clamps (bulldog pattern), two or three glass cannulae of 

 various sizes for bloodvessels, ten strong waxed ligatures, sponges, 

 hot water, a towel or two, and a pair of bellows to be connected 

 with the tracheal cannula when the chest is opened. Arrange an 

 induction-coil and electrodes for a tetanizing current (Fig. 65, p. 175). 

 With scissors curved on the flat clip away the hair from the front of 

 the neck and the anterior surface of one thigh below Poupart's 

 ligament. Put the hair carefully away, and remove all the loose 

 hairs with a wet sponge so that they may not get into the wounds. 

 If the animal is not fully anaesthetized, give ether. Insert a glass 

 cannula, which should have a piece of indiarubber-tubing 2 to 3 

 inches in length on its wide end, into the central end of the femoral 

 vein. Feel for the femoral artery, cut down over it, and with forceps 

 or a blunt needle separate the femoral vein from it for about an inch. 

 Pass two unwaxed ligatures under the vein, and tie a loose loop on 

 each. Put a pair of bulldog forceps on the vein between the liga- 

 tures and the heart. Now tie the lower (distal) ligature, and cut one 

 end short. The piece of vein between it and the bulldog forceps is 

 thus distended with blood, and this facilitates the next step. With 

 fine-pointed scissors make a snip in the wall of the vein. The 

 cannula is now pushed through the slit in the vein, and the upper 

 ligature tied firmly round its neck. By the aid of a pipette, made by 

 drawing a piece of glass tubing out to a long point, the cannula and 

 rubber tube are then completely filled with normal saline solution. 

 Be sure to pass the point of the pipette right down to the point of 

 the cannula, so as to dislodge any bubble of air that may tend to 

 cling there. Then, holding up the open end of the rubber tube, 

 close it, without allowing any air to enter, by means of a screw clamp 

 or bulldog forceps, or a small piece of glass rod. i or 2 cc. of 

 the 2 per cent, solution of morphia may be injected from time to 

 time, when necessary, by pushing the needle of the hypodermic 

 syringe through the rubber tube. When the needle is withdrawn the 

 little hole closes completely, and nothing escapes from the cannula. 



To put a Cannula in the Trachea. The hair having been clipped 

 in the middle line of the neck and the skin shaved, a mesial incision 

 is to be made, beginning a little below the cricoid cartilage, which 

 can be felt with the finger. The trachea is then cleared from its 

 attachments by forceps or a blunt needle, and two strong ligatures 

 are passed beneath it. A single loop is placed on each of those, 

 but is not drawn tight. Raising the trachea by means of the upper 

 ligature, the student makes a longitudinal incision through two or 

 three of the cartilaginous rings, inserts the cannula, and ties the 

 lower ligature firmly around its neck. It is well also, though not 

 necessary, to now tie the upper ligature, and additional security may 

 be obtained by tying together the ends of the two ligatures around 

 the cannula. 



Clip off the hair on each side of the sternum. Mak* an incision 

 on each side through the skin and down to the costal cartages about 

 2 inches from the edge of the breast-oone, and long enough to 



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