270 BACTEEIOLOGY. 



is employed. The necessary directions will be found under 

 that head (Chapter XIV). 



5. — Intra-pleural injection. — This method is sometimes 

 employed, though rarely. Great care must be taken to 

 prevent injury to the lungs or heart. The introduction of a 

 larg-e quantity of liquid is in itself dangerous. The needle 

 is introduced into the right pleural cavity at some distance 

 from the median line. The results of infection are brought 

 on rapidly, as in the case of intraperitoneal injection. 



6. — Ivfection of the anterior chamber of the eye. — This 

 method has been followed with excellent results in the 

 study of tuberculosis. The pathological changes induced 

 can be observed from day to day. The operation itself is 

 simple. The eye is first anesthetized with cocain. An 

 incision is made, by means of a very narrow scalpel, at the 

 juncture of the cornea and sclera. Through the opening 

 thus made, the material to be tested is inserted into the 

 anterior chamber. Instead of making an incision the bac- 

 terial fluid can be injected by means of a syringe. 



7. — Infection of the lymphatics. — This is accomplished 

 easily by injecting directly into a testicle. The infection 

 spreads rapidly through the neighboring lymphatics and as 

 a result marked alterations result in a short time. 



8. — Intra-cranial injection. — This is the method employed 

 by Pasteur and his pupils in producing rabies in rabbits 

 and other animals. The procedure will be described in 

 Chapter XIV. 



9. — Infection along the respiratory tract. — This may be 

 brought about (1) by the inhalation of the finely divided 

 organisms; (2) by injection into the trachea. The former 

 method is analogous to the usual mode of infection in 



