514 OPEEATIONS ON THE CIECULATOEY SYSTEM. 



be obviated, seeing that it merely requires careful attention to 

 the execution of the few details -which constitute the act of vene- 

 section. But when it has taken place, the simplest and most ob- 

 vious thing to do is, if possible, to remove the air from the vessel 

 in which it has intruded. The means of effecting this consists in 

 reopening the closed vein, and permitting the blood to resume 

 its flow. The loss of three or four pounds of blood additional 

 is usually sufficient to insure the escape of all the air. Gourdon 

 recommends, in addition, showering with (jold water, stimulating 

 frictions, and even, if the case seems to require it, artificial 

 respiration. 



AETERIOTOMT. 



Bleeding from an artery is so termed to distinguish it from 

 phlebotomy. It is not commonly used in practice, being princi- 

 pally resorted to as a means of local depletion, and is performed 

 only on some of the mo»t superficial of the vessels. In fact, there 

 are but three of these eligible by their position to the operation. 

 These are the transveral of the face, the posterior auricular, and 

 the middle caudal. 



The modus operandi differs but little from that of phlebot- 

 omy, except that there is usually no need of the application of ar- 

 tificial means to sweU their bulk or increase their rotundity, their 

 position, and their distinct and characteristic pulsation, so readily 

 detected, sufficiently revealing their location and course. In open- 

 ing arteries the fleam is seldom used, the lancet or a pointed bis- 

 toury being a much more eligible instrument. The incision of the 

 vessel is made across its course instead of longitudinally, as in 

 phlebotomy, and the flow of blood must be arrested by meansof 

 pressure with compresses or bandages. 



(a) Sleeding at the Transversal of the Face. — Though the 

 position of this artery is nearly correspondent in all animals, it is 

 principally with solipeds' that it is chosen for blood-letting. It is 

 situated below the temporo-maxiUary articulation, and crossing 

 the direction of the fibres of the masseter muscle, where it is cov- 

 ered only by a fine skin, it is opened at the same level with the 

 place where phlebotomy is usually performed. Some operators 

 prefer casting the animal, others the standing position. 



The appearance of the vessel is that of a small, round pulsa^ 

 ting cord, and, as before stated, it is incised, not as the veins and 



