138 A MANUAL OF BACTERIOLOGY 



order to detach the collodion from the glass, the whole is 

 dipped for a few seconds alternately into strong spirit 

 and into water ; the collodion loosens, and may be easily 

 peeled off the glass. The sack may be sterilised by placing 

 in a test-tube and heating to 150 C. in the hot-air 

 steriliser. 



For the inoculation of animals various methods may be 

 adopted. Thus, after clipping the hair, the organism may 

 be introduced by rubbing into the skin after scarification, 

 or, a small incision having been made through the skin, 

 a small quantity of a culture may be introduced on a 

 platinum needle ; or a broth culture or an emulsion, 

 made with sterilised water or broth, may be injected with 

 a sterilised syringe subcutaneously, intravenously, intra- 

 peritoneally, or into the muscular or other tissues or 

 organs as required, since the seat of inoculation may have 

 to be varied for the different species to produce their 

 pathogenic effect. For injection purposes a syringe like 

 an antitoxin syringe, i.e. with asbestos or metal piston 

 and glass barrel that can be boiled, may be used. Several 

 sizes, 1 c.c., 2 c.c., and 5 c.c. at least, are required. An 

 all-glass syringe is a still better form, but is expensive. 

 For accurate dosage, the piston-rod should be graduated 

 and have a nut travelling on a screw up and down it. 

 Before use the syringe with the needle should be boiled 

 for ten minutes to sterilise it ; after use it may be well 

 rinsed and again boiled. The needles should be wiped 

 dry and a wire inserted, or they may be kept in a bottle 

 of xylol. 



Guinea-pigs and rabbits are usually inoculated in the 

 thigh or abdomen ; mice in the dorsal region or at the 

 root of the tail (dorsally), the hair being clipped, and 

 the skin disinfected, but this is not generally necessary. 

 Numerous mechanical holders have been devised for 

 animals, but are not as a rule required. Rabbits may 



