302 CLINICAL BACTERIOLOGY AND KLEMATOLOGY 



bro-spinal fluid for about two days, part of the haemoglobin is 

 converted into a yellow pigment; if, therefore, after centri- 

 fugalization the supernatant fluid is yellow, it indicates that 

 the blood was actually present in the cerebro-spinal fluid whilst 

 in the body, and that the haemorrhage had occurred two days 

 or more previously. If the supernatant fluid is colourless, 

 the blood came from the puncture, or had only been recently 

 effused. 



If, as sometimes happens, you can only get a few drops of 

 fluid from a lumbar puncture, it is not wise to attach any 

 importance to the presence of a moderate amount of blood. 

 The needle always picks up some corpuscles in its passage 

 through the parietes, and these may be quite obvious if not 

 diluted with a considerable amount of fluid. 



Large endothelial cells containing numerous red corpuscles 

 (similar cells to those shown on Plate X., Fig. 3) may appear 

 in the fluid after a cerebral haemorrhage. They do not make 

 their appearance until three or four days after the blood has 

 been poured out. 



Hemorrhage into the meningeal cavities or into the ven- 

 tricles is, of course, accompanied by blood in the cerebro- 

 spinal fluid. This may be found in cases of fracture of the 

 skull, especially of the base, or of the spinal column, or in 

 contusion of the brain, and it is worth noting that in some 

 cases there has been great relief of the symptoms after the 

 fluid has been drawn off. Lumbar puncture should always 

 be remembered as a means of diagnosis in patients found 

 unconscious. 



"SEPTIC" MENINGITIS i.e., that due to the meningococcus, 

 pneumococcus, streptococcus, typhoid bacillus, etc. is char- 

 acterized by the presence of large numbers of polynuclear 

 cells in the fluid. In all cases the numbers tend to be more 

 numerous than in tuberculous meningitis, and may run into 

 hundreds of thousands per cubic millimetre, in which case the 

 fluid resembles watery pus. 



The importance of this fact is very great, and the discovery 

 of polynuclear leucocytosis has led to the discovery that mild 

 cases of this affection occur which are hardly diagnosable 

 clinically, and which may be completely cured. According to 

 several French authorities, the first indication of commencing 



