THE COLLECTION OF FLUIDS FROM SEROUS CAVITIES 1 69 



the fluids which collect in the pleura, the membranes of the 

 brain and cord, and the joints. In some cases all the needful 

 information may be obtained by the examination of stained 

 films, cultures being unnecessary; and in these cases no anti- 

 septic or aseptic precautions (other than those which are dic- 

 tated by the interests of the patient) are necessary. But in 

 the greater proportion of cases this is not enough, and cul- 

 tures must be obtained. To this end it is absolutely essential 

 that the most scrupulous precautions should be taken against 

 contamination of the fluids by the organisms which are con- 

 stantly present in the air and in the skin, or the results will be 

 worthless. The precautions taken must be as complete as 

 those which are used before an operation upon a joint. 



The iodine method of preparing the skin, which is now so 

 g-enerally used for surgical purposes, is of especial value to 

 the clinical pathologist. The area to be punctured should be 

 painted with the tincture of iodine two or three times at inter- 

 vals of five or ten minutes, and the puncture can be made 

 without fear of contamination. It is an advantage to wash 

 the skin just before the operation with acetone ; this is in itself 

 an efficient antiseptic, and it removes the iodine, and so allows 

 the structures in the neighbourhood to be recognized more 

 distinctly. Where this precaution is not taken the iodine 

 sometimes causes a transient, but annoying, dermatitis. 



The puncture may be made by using some sort of explor- 

 ing syringe, or a hollow needle without any means for aspira- 

 tion. The former is used for the removal of fluid from the 

 pleura or synovial cavity, the latter in performing lumbar 

 puncture. But it is necessary that the whole of the instru- 

 ment used should be rendered sterile by heat; chemical anti- 

 septics are as a rule inadmissible. The best method of effect- 

 ing this is that introduced by Sir Almroth Wright, of sucking 

 up oil at a temperature of 130 C. several times into the 

 syringe, or by dipping a needle, etc., into the same fluid for 

 half a minute or so. If no thermometer is at hand a crumb 

 of bread can be used to indicate the temperature. If bubbles 

 of steam are given off when it is dropped into the oil, the 

 latter is at or over 100 C.; if it is browned, the temperature 

 may be taken as being 130 C. or more. Failing this the 

 syringe, etc., may be boiled for five minutes, but this cannot 

 be relied on. to kill spores. 



