BY DR. KLEIN. Ill 



not to tear the canula out of the vein. If it is desired to 

 continue the injection for some time, it is better to employ the 

 pressure of a column of liquid, for which purpose the following 

 arrangement must be used : A moderate-sized flask, contain- 

 ing the injection liquid, is supported on a retort-holder at a 

 height of about two or three feet above the table. The Husk 

 is fitted with a cork, in which two tubes are fixed, the one 

 being straight for the admission of air, the other bent so as to 

 form a syphon, the short leg of which dips under the level of 

 the liquid. To the other end an india-rubber tube, furnished 

 with a screw-clamp, is fitted, long enough to reach the canula. 

 A current is now produced along the tube by suction, which 

 can be regulated by the clamp so as to allow the liquid to flow 

 in a rapid succession of drops. The tube is then momentarily 

 closed by a second clip, and connected with the canula. The 

 clip on the tube is now opened and that on the vein removed. 

 As soon as the injection is finished the vein is ligatured on the 

 proximal side of the canula, which is then withdrawn. In 

 long injections, it is of course necessary to open the peripheral 

 end of the vein. If it is desired to estimate the quantity of 

 liquid injected, a cylindrical bottle is substituted for the flask, 

 which must be previously graduated. When the object in view 

 is to replace the blood completely with salt solution (with or 

 without coloring matter), it is better to introduce the canula 

 into the bulbus arteriosus. 



Injection of small Mammalian Animals during life. 

 The animal is secured with the aid of Czermak's holder. 

 (See Chapter XVI.) The external jugular is then exposed 

 by a sufficient incision, and cleared of the sorrounding tissue 

 with the aid of dissecting forceps. The vessel having been 

 ligatured at the distal end of the prepared part, and a clip 

 placed on it at the central end, the vein is opened by a small 

 incision, and a proper canula inserted and secured with a 

 ligature. The canula is then filled with salt solution with the 

 aid of a capillary pipette, and connected either with the 

 syringe or the tube of the syphon previously described. 

 Finally, the clip is opened, and the liquid allowed gradually 

 to enter the vein. As boon as the injection is completed, the 

 clip is immediately closed. Before the canula is removed, the 

 vein is of course ligatured. If the quantity to be injected is 

 small, it is simpler to use a small subcutaneous syringe, in 

 which case all that is necessary is to compress the vein imme- 

 diately above the clavicle, and to pierce it, when distended, 

 with the point of the canula. The pressure having been 

 discontinued, the liquid is at once injected. The aperture 

 must be seized by means of clip-forceps as the caiiula is with- 

 drawn, so as to prevent bleeding. 



