ANTHRAX 57 



Interpretation of Results. 



If the case is really one of malignant pustule, the chances are 

 very greatly in favour of your finding the bacilli in large numbers, 

 and the failure to do so tells strongly against a positive diagnosis. 



Cultural Methods. — The fluid for examination is taken in exactly 

 the same way as that described above, but the isolation of the 

 organisms will be greatly facilitated if antiseptic methods are 

 employed to prevent contamination with skin bacteria. To this 

 end the surface of the lesion should be washed gently with 

 carbolic or perchloride lotion, and then (very thoroughly) with 

 alcohol or methylated spirit to remove the antiseptic. The 

 surface is then allowed to dry. 



If the material is to be transmitted to a pathologist for examina- 



FiG. 19. — Petri's Dish. 



tion (and this is the wisest course to adopt, as animal inoculations 

 are almost necessary for the absolute identification of the bacillus), 

 the fluid must be carefully sucked up into the bulb, and both ends 

 of the pipette carefully sealed. 



If the examination is to be made at home, the best way is to 

 make two inoculations in gelatin. The first should be a stab 

 culture, and may be made with the pipette direct ; or the fluid 

 may be blown out into a watch-glass or on to the surface of a 

 slide (in either case sterilized by being heated in the flame and 

 then allowed to cool), and the stab made by dipping the end of a 

 straight platinum needle into the fluid, and then driving it into the 

 gelatin. 



The other culture is made with the pipette ; this is driven into 

 the gelatin in a tube and the contents blown out. The gelatin is 

 then immersed in warm water until it is melted, and poured out 

 into a Petri's dish (Fig. 19) previously sterilized by dry heat and 

 allowed to cool. 



Both cultures are incubated at a temperature of about 20° C. 



In about two days the gelatin stab-tube will show a very 



