122 GENERAL BACTERIOLOGICAL DIAGNOSIS. 



by containing some of the antiseptics used in the purifica- 

 tion) and a little of what subsequently escapes allowed to 

 flow into a sterile test-tube. If test-tubes sterilised in a 

 laboratory are not at hand, an ordinary test-tube may be a 

 quarter filled with water, which is then well boiled over a 

 spirit-lamp. The tube is then emptied and plugged with a 

 plug of cotton wool, the outside of which has been singed 

 in a flame. Small stoppered bottles may be sterilised and 

 used in the same way. A discharge to be examined may 

 be so small in quantity as to make the procedure described 

 impracticable. It may be caught on a piece of sterile plain 

 gauze, or of plain absorbent wool, which is then placed in a 

 sterile vessel. Wool or gauze used for this purpose, or for 

 swobbing out, say the throat, to obtain shreds of suspicious 

 matter, must have no antiseptic impreg- 

 nated in it, as the latter may kill the 

 bacteria present and make the obtaining 

 of cultures impossible. 



Fluids from the body cavities, urine, 

 etc., may be secured with sterile pipettes. 

 To make one of these, take nine inches 

 of ordinary quill glass -tubing, draw out 

 one end to a capillary diameter, and place 

 a little plug of cotton wool in the other 

 end. Insert this tube through the cotton 

 plug of an ordinary test-tube and sterilise 

 by heat. To use it, remove test-tube plug 

 with the quill tube in its centre, suck up 

 some of the fluid into the latter, and re- 

 place in its former position in the test-tube 

 (Fig. 42). Another method very convenient 

 for transport is to make two constrictions 

 tube and pipette on tne glass tube at suitable distances, ac- 



arranged for obtain- 

 ing fluids contain- 

 ing bacteria. 



FIG. 42. Test- 



cording to the amount of fluid to be taken. 

 The fluid is then drawn up into the part 

 between the constrictions, but so as not to 

 fill it completely. . The tube is then broken through at both 

 constrictions and the thin ends are sealed by heating in a flame. 



