OBTAINING LARGE AMOUNTS OF ANIMAL BLOOD 



43 



injection of a gram of chloral hydrate in 10 c.c. of water, deep sleep being 

 induced by the latter in from five to ten minutes, and lasting for several 

 hours, during which time operative procedures produce no pain. 



First Method (Nuttall). The animal is fastened to an operating 

 board, or, preferably, held by an assistant, and the hair over the neck 

 and thorax is moistened with a 1 per cent, lysol solution.' By means 



FIG. 20. A DISSECTION OF THE NECK OF A RABBIT TO SHOW THE RELATIONS OF 



THE CAROTID ARTERY. 

 T, trachea; A, carotid artery; V, internal jugular vein; V.N., vagus nerve. 



of a sterile knife the skin is cut longitudinally and the neck muscles ex- 

 posed for a considerable distance. The animal is then held upright by 

 the assistant over a sterile dish or a large sterile funnel, emptying into 

 a cylinder or 50 c.c. centrifuge tube. The operator stretches the neck 

 by carrying the head backward, and severs the large vessels on one or 

 both sides of the neck with a sharp sterile scalpel or razor, avoiding 



