164 CLINICAL BACTERIOLOGY AND HiEMATOLOGY 



this reason we are chary of recommending this method ot 

 diagnosis in any hands other than those of an expert, and must 

 urge the practitioner not to attempt it unless he is prepared to 

 carry it out properly in the most minute detail. It is in particular 

 absolutely useless to attempt to obtain cultures with the blood 

 taken from a skin puncture ; it must be drawn direct from a 

 vein, and a large quantity (not less than i c.c, and preferably 

 4 or 5, or even 10) must be employed. 



One plan is to use a hypodermic needle, and to plunge it 

 directly into a vein. The process may be carried out as 

 follows : 



Requisites. — i. An all-glass hypodermic syringe of at least 5 c.c, 

 and better 10 c.c, capacity, preferably furnished with platino- 

 iridium needle. 



2. Means of sterilizing the above. I personally keep the 

 syringe always sterilized with carbolic lotion (i in 20). After use 

 at any time it is washed out with the lotion, a little of which is 

 allowed to remain in the barrel, which is thus always sterile. 

 Before use the antiseptic has to be removed, and this is effected 

 by filling the syringe two or three times with sterile nutrient 

 broth, a spare culture tube being taken for the purpose. This 

 gets rid of the waste of time involved in boiling, and the necessity 

 for carrying cumbrous sterilizers. 



Another method is to boil the instrument for ten minutes. 



Or Wright's method may be adopted. Oil is heated to 150° in 

 a metal capsule, and the syringe washed out two or three times 

 with the hot oil. If no thermometer is at hand the temperature 

 of the oil can be estimated roughly by dropping a crumb of bread 

 into it. If the crumb gives off bubbles, the temperature is 100° or 

 above ; it is turned brown at 150°- 



3. Materials for sterilizing the skin are described under the 

 heading of Lumbar Puncture. 



4. A narrow bandage or piece of tape. 



5. A spirit-lamp (not indispensable). 



6. Cultitre Tubes. — On the whole broth is the most suitable 

 media, and rather large tubes, containing about 25 c.c. of broth, 

 the best to use. One or two cultures on agar should also be 

 taken. 



7. Collodion, to be applied to the puncture after the operation. 

 Method. — Apply the narrow bandage to the upper arm suffi- 

 ciently tightly to obstruct the venous circulation, but not tightly 



