SERUM 



49 



which, when the trocar is withdrawn, a metal adjustment can be fitted ; 

 this carries a piece of red rubber tubing about 50 cm. long, to which is 

 attached a piece of glass tubing 15 cm. long bevelled at its free end. 



The trocar and the rubber tube with its appendices are wrapped separately 

 in filter paper and autoclaved. 



Sivori's trocar (fig. 38) may with advantage be employed instead of Nocard's ; 

 it is provided with a lateral tube E to which the rubber tubing is attached. The 

 trocar with tubing attached can be sterilized as a single piece of apparatus, and the 

 blood collected directly, thus avoiding any risk of contamination. 



FIG. 38. Sivori's trocar. 



M, handle ; C, shoulder into which the conical part AB fits hermetically, so 

 that the blood flows up the cannula D, and passes out through E. 



2. A pair of sterile scissors curved on the flat and a sterile bistoury. 



3. One or two wide-mouthed bottles of 3 litres capacity. 



The bottles are washed and dried, and the mouth of each covered with two 

 or three folds of paper which is tied down round the neck with string ; over 

 this another similar but larger covering is fastened with string in a similar 

 manner, so that it can be removed without interfering with the cover beneath 

 (fig. 39). The bottles must be sterilized in the hot air sterilizer. 



4. Some sterile Chamberland flasks and test-tubes. 



Technique. As a rule, blood is taken from an horse or an ass while the 

 animal is standing. If necessary its eyes can be covered and the animal can 

 be held with a twitch. If it is proposed to bleed a 

 bovine animal, it will be best to throw it on a 

 table such as is used for vaccination inoculations. 1 

 The animal, whichever species is used, should be 

 fasting. 



1. Proceed as for bleeding from the jugular vein. 

 Sterilize the skin. Press the vein at the root of 

 the neck to render it prominent, and make a small 

 longitudinal incision through the skin with a bistoury 

 along the line of the vessel on the distal side of the 

 point of compression. 



2. Introduce the trocar through the incision and 

 push it through the sub-cutaneous tissues for a 

 distance of about 2 cm., then pierce the vein and 

 push the trocar into it in the direction of its long 

 axis. 



3. The cannula is now in place ; withdraw the 

 trocar, and attach the metal adjustment carrying 

 the rubber tube. Meanwhile an assistant com- 

 presses the vein above to prevent blood entering 

 the cannula. This must be done quickly. 



4. The rubber tube being attached, pinch it firmly 



between the thumb and index finger of the left hand. The assistant releases 

 the pressure on the vein above the cannula, but maintains the pressure on 

 the cardiac side. 



I 1 In our experience it has never been necessary to throw a bovine animal : adults 

 usually stand quite quietly.] 



T\ 



. 39. -Bottle for collecting 



Part of the outer cover has 

 SSath m ved t0 Sh W the One 



