REMARKS ON GENERAL PROCEDURE. 



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 stop- 

 pered 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 pur- 

 pose, or for swabbing out, say the throat, to obtain shreds of 

 suspicious matter, must have no antiseptic impregnated 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 replace in its former position in 

 the test-tube. (Fig. 54.) Another method very 

 convenient for transport is to make two constric- 

 tions on the glass tube at suitable distances, 

 according 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 com- 

 pletely. The tube is then broken through at 

 both constrictions and the thin ends are sealed 



'*-~Xf r 



by heating in a flame. FIG. 54. Test- 



o T i , , , , , ... . tube and pipette 



Solid organs to be examined should, if possi- arrange d for ob- 

 ble, be obtained whole. They may be treated in taining fluids con- 



r taining bacteria. 



one of two ways. i. The surface over one part 

 about an inch broad is seared with a cautery heated to dull red 

 heat. All superficial organisms are thus killed. An incision 

 is made in this seared zone with a sterile scalpel, and small 

 quantities of the juice are removed by a platinum loop to make 

 cover-glass preparations and plate or smear cultures. 2. An 



40; 



