AND HOW TO USE IT. 171 



chloroform, or immediately after it has been suffocated by 

 chloroform. To facilitate the bleeding, the animal should be 

 suspended alternately by the hind and front legs, and as the blood 

 coagulates in the wound in the heart it should be removed. The 

 best plan to administer the chloroform is to place the animal in a 

 box, drop in a piece of cotton wool saturated with chloroform, 

 and close the lid. In from five to fifteen minutes the animal will 

 be dead. 



To Inject a Whole Animal. — A rabbit is perhaps the best 

 subject for a beginner. After killing it immerse the body in hot 

 water for about fifteen minutes ; then take it out, pass a ligature 

 round the aorta close to the heart, make a longitudinal incision in 

 the aorta, and insert a cannula of most suitable size. Bind the 

 cannula firmly in the artery, and attach the stop-cock. Floss silk 

 or oiled worsted are the best substances which can be employed for 

 tying pipes in the vessels ; it should not be drawn too tight or it 

 will cut through them, and so permit the pipe to come out. All ves- 

 sels must be opened longitudinally and under water: this prevents 

 the entrance of air ; avoid making the slit too large. If the cut 

 be transverse the vessel may be torn in two, or contract so much 

 as to be difficult to get hold of and so exclude the possibility of 

 making an injection. Have a good supply of hot carmine mass 

 (Dr. Carter's). First fill the syringe with the injection and then the 

 stop-cock and cannula ; then insert the nozzle of the syringe into 

 the stop-cock, taking care that no air is admitted, or the passage of 

 fluid will be impeded. The amount of pressure exerted on the 

 piston should at first be very slight, but gradually increased as the 

 injection proceeds. The filling of the spleen should be carefully 

 watched, and as soon as fully distended, more injection mass 

 should be prevented from flowing into it by tying a ligature round 

 its artery. 



The splenic artery is easily found. It arises as a branch 

 of the coeliac axis, and enters the substance of the spleen at 

 the hilus on its concave surface. In order to obtain a perfect 

 injection of the kidney, it should be drained of all blood by 

 opening the renal vein. Blood and carmine mass will at first flow 

 out together; but as soon as the carmine flows out freely and un- 

 mixed with blood, the vein should be ligatured, and the vessels 



