284 APPENDIX. 



IX. On Injections. Blood vessels and other tubular organs and 

 ducts are much more easily studied if first filled with some colored 

 substance which renders them more conspicuous. The following 

 Starch Injection Mass is recommended for filling such vessels : 



Tarta. 



Dry (laundry) starch 40 



Water or (better, if to be kept) 2i% solution chloral hydrate . 40 



95% alcohol 10 



Color mixture 10 



These should be thoroughly mixed and the mixture strained 

 through cheese-cloth. 



It is easily prepared, easily used, and, on the whole, gives very satis- 

 factory results. A syringe of some sort may be necessary for forcing the 

 mass into the vessels to be injected. A cannula should be attached by a 

 short bit of rubber tubing to the end of the syringe. The cannula is 

 for insertion into the end of the vessel to be injected. It may readily 

 be made of a piece of glass tubing drawn to a point, with a constriction 

 made near the point to hold a ligature from slipping off when tied 

 around it. It is well to have several cannulae with nozzles of different 

 sizes. A rubber bulb on a cannula made from a glass tube will answer 

 ordinarily for any animal not larger than a cat. 



The formula for the color mixture mentioned in the above is as 

 follows : 



Dry color (vermilion, red lead, Berlin blue, ultramarine blue, Parts. 



chrome yellow, orange, or green) 3 



Glycerine 3 



95% alcohol 3 



These should first be thoroughly mixed by grinding together in a 

 mortar. 



This starch mass will keep indefinitely in a well-stoppered bottle, 

 and only needs to be shaken to be ready for use. In using it, the 

 syringe is first filled with it. The cannula is attached to the syringe, 

 filled by pushing on the piston slightly, inserted into the end of the 

 vessel to be injected, and ligatured fast by a soft cotton string tied 

 around the outside of the vessel. The vessel is then filled by a steady, 

 gentle pressure upon the piston of the syringe. 



A verv convenient instrument for passing the ligature around the 

 vessel to be tied, may be made by pushing the point of a darning 

 needle into a wooden handle, heating the eye end of the needle red-hot 

 and bending it into a shallow hook. The needle can be threaded with 



