v.] METHODS OF INOCULATION. 45 



clean well with soap and water and then with strong carbolic 

 acid or perchloride of mercury solution the tip of a finger, 

 make a venous congestion in the last phalanx by compressing 

 it with a corner of a handkerchief, prick the volar skin 

 of the phalanx with a clean (overheated and cooled) needle, 

 and plunging the pointed end of the pipette into the drop 

 of blood, allow a droplet to ascend into the capillary tube of 

 the pipette. 



If solid tissues or parts of tissues are required, e.g. the 

 base of an ulcer, a tubercle of the liver, spleen, or lung, it is 

 possible to squeeze into the capillary tube of a pipette, after 

 pushing its pointed end into the part, a small droplet of 

 juice of the part required ; but if this be not practicable, i.e. 

 if a solid particle be required, then follow Koch's method. 

 This is as follows : Cut with clean scissors or scalpel into the 

 part, dig out rapidly with the point of a needle or platinum 

 wire previously overheated in the flame of a burner a small 

 particle, and quickly introduce this into the culture-tube to 

 the place required, e.g. surface or depth of a solid or fluid 

 nourishing material. Of course in this case the cotton-wool 

 must be altogether lifted, and therefore contamination with 

 organisms is possible. But inoculating several tubes at once 

 and performing the operation quickly, one always succeeds 

 in getting some of the tubes without any air-contamination. 

 I have made numerous inoculations with solid particles 

 (tubercles) in this manner, and like Koch have seen only a 

 small percentage of tubes going bad through contamination 

 with air-organisms. 



The same plan, i.e. of using the clean point of a needle or 

 platinum wire for taking up the material to be used for 

 inoculation, is resorted to if one has to deal with the culture 

 in solid nourishing material, on or in which the organisms 

 are growing that we want to transplant either for inoculation 



