ANIMALS AFTER INOCULATION. 221 



Illation 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 

 tuberculous 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 that is unusual in its conduct noted — as, for instance, 

 elevation of temperature; loss of weight ; peculiar posi- 

 tion in its cage; loss of appetite; roughening of the 

 hair ; excessive secretions, either from the air-passages, 

 conjunctiva, or kidneys; looseness of or hemorrhage 

 from the bowels; tumefaction or reaction at site of inoc- 

 ulation, etc. If death ensue in from two to four days, 

 it may reasonably be expected that at autopsy evidence 

 of either acute septic or toxic processes will be found. 

 It sometimes occurs, however, that inoculation results 

 in the production of chronic conditions, and the animal 

 must be kept under observation often for weeks. In 

 these cases it is important to note the progress of the 

 changes by their effect upon the physical conditions of 

 the animal, viz., upon the nutritive processes as evi- 

 denced by fluctuation in weight, and upon the body 

 temperature. For this purpose the animal is to be 

 weighed daily, always at about the same hour and 

 always about midway between the hours of feeding; 

 at the same time its temperature as indicated by a ther- 



