POST-MORTEM EXAMINATION OP INFECTED ANIMALS. 275 



the common putrefactive bacteria from the intestinal canal. 

 Consequently, in delayed examinations, impure cultures are 

 apt to be met with. Moreover, an uncertainty will exist 

 as to whether the secondary invasion occurred during* life, 

 or after death. Hence, in case the animal cannot be exam- 

 ined at once, it should be placed in a suitable vessel and 

 kept on ice. 



FIG. 48. a Searing iron; b Instrument sterilizing case. 



All the necessary instruments should be sterilized be- 

 fore use. This may be done by heating the instruments, di- 

 rectly in the flame. Inasmuch as this procedure destroys 

 the temper it should be avoided as much as possible. The 

 best method of sterilizing" instruments, is to place these on 

 a perforated tray which is then immersed in a copper or 

 enameled iron box. The box should contain an almost sat- 

 urated solution of borax (10 per cent.). The borax is to be 

 preferred to sodium carbonate, since it prevents tarn- 

 ishing as well as rusting of the instruments. The latter 

 can be kept constantly in the borax solution. When it is 

 desirable to sterilize these the box is placed on a Fletcher 

 radial burner. In a few minutes the liquid will boil activ- 

 ely. After 3 to 5 minutes of boiling, the flame can be turned 

 off. This instrument sterilizer is shown in Fig. 48 &. 



A searing iron, also shown in Fig. 48, several sterile 

 drawn out pipettes (Fig. 61), and several tubes of gelatin, 



