COLLECTION OF PUS. 135 
brain. This may assist in the diagnosis of obscure 
injuries, or of the cause of a case of unconsciousness in 
which no history can be obtained. 
Hemorrhage into the meninges is indicated by the 
withdrawal of blood-stained fluid, but it must be 
remembered that the first few drops may contain a 
small quantity of blood which has entered the needle 
during its passage through the tissues, while the rest is 
clear. Blood-stained fluid may occur in meningitis, 
and should be submitted to a full examination for 
leucocytes and bacteria. 
Transmission of fluid to public labovatory.—If the prac- 
titioner is unable to examine the fluid the best method 
to adopt is to collect it in a long and narrow test tube 
(sterilised by dry heat) and to seal the neck of the tube. 
Or he may forward it in a bottle sterilised by boiling 
and plugged with a cork which has also been boiled, 
but this method is not so good. 
THE COLLECTION OF PUS. 
When a simple microscopical examination has to be 
made the collection of pus presents no difficulties, as 
the few bacteria which may gain access from the skin 
or the air will not lead to error. The case is otherwise 
where cultural examinations have to be made, or where 
the material has to be transmitted to a laboratory. 
Here the material should be collected in a pipette. 
This is to be at hand when the abscess is opened; both 
ends are to be broken off and passed through the flame 
two or three times. The pipette should then be held 
by an assistant or put with the end which is to be 
inserted into the pus projecting over the side of the 
table so as not to come into contact with any object. 
