58 BACTERIOLOGICAL DIAGNOSIS. 



from the air, and the glucose is added to absorb any 

 oxygen which may be in the medium. To increase our 

 chances of obtaining this bacillus in pure culture the 

 material to be examined is to be heated to a tempera- 

 ture which will kill all developed bacteria, but which 

 will not be injurious to spores ; the tetanus bacillus is 

 the only anaerobic organism with a spherical terminal 

 spore which is at all likely to occur in a wound. 



Method. The inoculations are to be made with a 

 pipette. If the pus which comes from the wound can 

 be drawn up into the capillary tube of a glass pipette 

 such as is described on page 41, the material should be 

 collected in this way. If this is not the case the wound 

 must be scraped with a sterilised platinum needle or 

 other suitable instrument and the material thus obtained 

 mixed with some boiled water (previously cooled) and 

 then sucked up into the pipette ; the end of the latter is 

 then to be sealed in the flame, care being taken that the 

 material itself is not heated. 



Having filled and sealed the pipette, heat some water 

 in a small flask or large test-tube until it reaches 80 C., 

 as measured by the thermometer ; insert the sealed end 

 of the pipette in the water and maintain the tempera- 

 ture for ten minutes. The thermometer is to be kept in 

 the water the whole of the time, and the flame is to be 

 taken away when the temperature rises above 80 C. 

 and reapplied when it falls below that point. 



At the end of this time the pipette will contain no 

 living object other than spores. Break off its point and 

 insert it gently into the glucose agar, taking care to 

 keep exactly in the axis of the tube, until the tip of the 

 pipette reaches almost to the bottom of the test-tube. 

 Withdraw the pipette gradually, blowing out its con- 

 tents as you do so. The spores of the tetanus bacillus 



