INTRODUCTION. 



21 



mass and the latter with a blue mass. These fluid masses 

 should be of such a character as to harden in a short 

 time after injection, so that they will 

 not run out when the vessels are cut 

 during dissection. 



A syringe of hard rubber, having a 

 capacity of about two ounces, serves 

 very well for injection. A cannula of 

 correct size may be had by asking the 

 druggist for the filling cannula of the 

 Parke Davis serum syringe. The end 

 to be inserted into the blood-vessel 

 should be ground off obliquely and 

 smoothly on a whetstone. The connec- 



/ 



tion between the cannula and nozle is 

 formed by stiff rubber tubing which 

 should be securely tied to the cannula 

 (Fig. 2). 



The injecting mass is prepared by 

 thoroughly mixing TOO c.c. of water, 20 

 c.c. of glycerin, 20 c.c. of concentrated 

 formalin, and 85 gm. of common laun- 

 dry starch. One-half should be colored 

 red by adding to it one or two grams 

 of powdered carmin made into a paste 

 with a few drops of ammonia, and the 

 other colored blue by dissolving in it a 

 gram or tw T o of soluble Berlin blue. 

 These liquid masses, after being passed 

 through a fine wire strainer or a coarse 



o 



piece of cheese-cloth stretched across a 



funnel, may be preserved for any length of time in covered 



jars. 



The animal may be anesthetized by placing it in a 



FIG. 2. INJECTING 

 SYRINGE. : . 



p, Plunger handle; 

 b, barrel ; pi, 

 nozle ; c, cannula ; 

 r, rubber tube ; <it, 

 point of detach- 

 ment; s, string. 



