APPENDIX 337 



known dull-tipped intravenous variety (N, Fig. 61). If it be 

 necessary to cut the skin, the wound must be closed by a 

 suture. 



Great care should be exercised to see that the tip of the 

 needle lies within the vein, because the escape of the salvar- 

 san solution into the subcutaneous and perivascular tissues 

 is productive of great pain, cellular infiltration and pro- 

 longed induration and nullifies the advantage of the intra- 

 venous over the intramuscular method of administration. 

 For this reason, it is well to have the needle and rubber 

 tubing filled with normal salt solution, which will not produce 

 irritation should it be allowed to escape into the subcutaneous 

 areolar tissue. If, by accident, a quantity of salvarsan solu- 

 tion should be allowed to infiltrate the perivascular tissues, 

 it is advisable to incise the overlying skin immediately, using 

 an anaesthetic of novocain or eucaine, wash out the salvarsan 

 with normal saline, and then to puncture the vein directly. 

 So soon as the vein has been entered, the tourniquet is 

 loosened, the cocks of the burette and needle turned on, 

 and the solution of salvarsan permitted to flow very slowly 

 from the burette. The temperature of the solution just 

 before entering the vein can be read from the thermometer 

 and should be blood heat. The introduction of the solution 

 should not take less than 10 minutes. Just before the sal- 

 varsan solution in the burette falls to the level of the stop- 

 cock, it should be turned off, cr the rubber tubing tempo- 

 rarily compressed and about twenty-five cubic centimetres 

 more of salt solution filtered into the burette, when the com- 

 pression is released or the stop-cock again turned on. This 

 procedure permits of the patient receiving the full amount 

 of salvarsan and at the same time suffices to wash the vein 

 free of salvarsan, thereby avoiding the possibility of phle- 

 22 



