LUMBAR PUNCTURE 149 



and not removed until the puncture has been made. Where 

 a sterilizer large enough to take the two instruments fixed 

 together is not at hand the needle may be placed point down- 

 ward in a test-tube half full of water, and the forceps inserted 

 as far as it will go by its side. The tube is boiled for ten 

 minutes and the needle removed by clipping it with the forceps, 

 as above. The handle will not be sterilized, but that does not 

 matter. 



I have devised a curved needle with a handle fitting into a 

 socket (Fig. 27), which also answers well. It has the advantage 

 that it can be put in a wide tube plugged with cotton-wool, 

 sterilized by dry heat, and taken to the bedside ready for 

 immediate use. 



2. Materials for disinfection of the patient's skin and (if cultures 

 are to be taken) the hands of the operator. Hot water, soap, 

 alcohol, ether, perchloride lotion (i in 1,000), or tincture of iodine 

 and acetone. 



3. Apparatus for boiling the needle in a dilute solution of 

 washing soda.* 



4. Spray for local anaesthesia. If this is used the hard plaque 

 of skin adds considerably to the difficulty of the operation. If, 

 however, the region be frozen twice, and allowed to thaw after 

 each freezing, the skin will be found to have resumed its normal 

 texture and to be very fairly ansesthetic. 



5. Two or three test-tubes sterilized by dry heat and plugged 

 with dry cotton wool. 



6. If cultures are to be taken, the tubes of medium should be 

 inoculated at the time of the operation if possible. The medium 

 required will depend to a great extent upon the nature of the 

 organism which is expected. If there are no indications upon 

 this point, the most suitable is solidified blood-serum, but in 

 default of this ordinary agar will answer well. If the case is 

 thought to be one of cerebro-spinal fever, the most suitable 

 medium for the cultivation of the specific organism (Weichsel- 

 baum's Diphcoccus intracellularis) is alkaline 5 per cent, glycerin- 

 agar, and a couple of tubes of this should be at hand, as well as 

 blood-serum or ordinary agar. 



* If possible, the needle should be sterilized by dry heat previous to the 

 operation, and kept in a tube plugged at both ends with cotton-wool, as in 

 the method recommended for the collection of blood for bacteriological 

 examination. 



