ANIMALS AFTER INOCULA TION. 225 



precautions, to avoid complications. All instruments, 

 sutures, ligatures, etc., must be carefully sterilized either 

 in the steam sterilizer for twenty minutes, or by boiling 

 in 2 per cent, sodium carbonate solution for ten min- 

 utes ; the hands of the operator, though they should not 

 touch the wound, must be carefully cleansed, and the 

 material to be introduced into the abdomen should be 

 handled with only sterilized instruments. 



Inoculation into the pleural cavity is much less fre- 

 quently required in fact, it is not a routine method. 

 It is not easy to enter the pleural cavity with a hypo- 

 dermic needle without injuring the lung, and it is rare 

 that conditions call for the introduction of solid parti- 

 cles into this locality. 



Inoculation into the anterior chamber of the eye is per- 

 formed by making a puncture through the cornea just 

 in front of its junction with the sclerotic, the knife being 

 passed into the anterior chamber in a plane parallel to 

 the plane of the iris. By the aid of a fine pair of for- 

 ceps the bit of tissue is passed through the opening thus 

 made and is deposited upon the iris, where it is allowed 

 to remain, and where its pathogenic activities upon the 

 iris can be conveniently studied. It is a mode of inoc- 

 ulation of very limited application, and is therefore but 

 rarely practised. It was employed in the classical 

 experiments of Cohnheim in demonstrating the infec- 

 tious nature of tuberculous tissues, tuberculosis of the 

 iris being the constant result of the introduction of tuber- 

 culous tissue into the anterior chamber of the eye of rabbits. 



OBSERVATION OF ANIMALS AFTER INOCULATION. 

 After either of these methods of inoculation, particu- 

 larly when unknown species of bacteria are being tested, 

 the animal is to be kept under constant observation and 

 all deviations from the normal are to be carefully noted 



15 



