I/O CLINICAL BACTERIOLOGY AND H/EMATOLOGY 



We shall now deal with the most important cavities of the 

 body, describing the methods to be employed in the investiga- 

 tion of the inflammatory exudates which they may contain, 

 and the inferences which may be drawn from the results of 

 the examination. 



THE PLEURA 



There is but little to be said about the method to be em- 

 ployed in the collection of fluid from the pleural cavities. The 

 most careful antiseptic precautions are to be taken, and the 

 region to be punctured should be decided by consideration of 

 the physical signs. 



The examination of the fluid thus obtained may be either 

 microscopical, cultural, or by injections into animals. If the 

 latter are required (and inoculation should be performed in 

 all cases where a tuberculous origin is suspected) a consider- 

 able quantity of the fluid an ounce or more should be en- 

 closed in a bottle which has been sterilized by boiling, and 

 forwarded at once. A drachm or more of 10 per cent, sodium 

 citrate solution (boiled) should be added to prevent coagula- 

 tion. 



Where the diagnosis is to be made by cultural methods, 

 and the cultures are not to be made on the spot, the fluid is 

 best stored or sent to a laboratory in pipettes. These are to 

 be filled from the syringe direct; the needle is to be removed, 

 and the end of the pipette (sterilized by being passed through 

 the flame) is passed into the fluid, and filled by gentle suction 

 at the other end. Each end is then sealed in a flame, care being 

 taken not to heat the fluid. Two or three such tubes should 

 be sent. 



Clear fluid from the chest rarely shows any micro-organ- 

 isms on microscopical examination. Cultures are usually 

 sterile; where streptococci or pnetimococci are found the in- 

 flammation is likely to pass on into suppuration. The great 

 majority of these cases of " simple " acute pleurisy are really 

 due to the tubercle bacillus, but their true nature is difficult 

 to determine except by inoculation experiments. A cyto- 

 logical examination of the fluid should be made, and in tuber- 

 culous cases the cells present will usually be found to be 

 lymphocytes, with an occasional admixture of blood-cor- 



