184 CLINICAL BACTERIOLOGY AND H^MATOLOGY 



such as indicate that meningitis is present, the presumption is 

 that the case is one of tuberculous meningitis. Films should 

 be stained in the method already described and carefully 

 searched; the bacilli are present in very scanty numbers, and 

 many films may have to be examined before one is found (see 

 also p. 185).* 



Cultural Examination. The tubes which have been inocu- 

 lated by allowing the fluid to drop directly on to the surface of 

 the medium are to be incubated for twenty-four hours at the 

 body temperature. Streptococci, staphylococci, pneumococci, 

 and the rare organisms, will probably have developed by this 

 time, and will have formed colonies such as have been pre- 

 viously described. WeichselbaunYs diplococcus forms (on 

 blood-serum) " round, whitish, shining, viscid-looking colonies, 

 with smooth, sharply defined outlines which attain a diameter 

 of I to i J millimetres in twenty-four hours." The colonies on 

 agar are similar, but slightly larger, and the growth may 

 become confluent. It is dealt with more fully on p. 108. 



If no colonies appear on blood-serum or agar at the end of 

 forty-eight hours, the case is probably due to the tubercle 

 bacillus or the gonococcus. In some cases of cerebro-spinal 

 fever the diplococci in the exudate are all dead, and cultures 

 remain sterile. 



INTERPRETATION 'OF RESULTS. 



The discovery of Weichselbaum's diplococcus indicates that 

 the case is one of cerebro-spinal- fever. It is in these cases 

 that repeated lumbar puncture is of therapeutic value; it 

 should be done whenever pressure symptoms are urgent. In 

 some of these cases also great benefit can be obtained from 

 vaccine treatment or from the intraspinal injection of anti- 

 meningococcic serum. The vaccine should be prepared from 

 the patient's own culture. The method is, of course, useless 

 in very rapid cases, but very good results are obtainable in the 

 more chronic ones. In some the immediate benefit resulting 

 from each injection is most marked. 



* Lenharz adds a shred of clean cotton-wool to the fluid. This sinks 

 slowly to the bottom, and is withdrawn after some hours, spread on a slide, 

 dried, and stained for tubercle bacilli. The author has had no experience of 

 this method, but Mr. Leedham-Green informs him that it is of considerable 

 value. 



