APPARATUS, MATERIAL, AND REAGENTS. 39 



terminates in an oblique opening, and is also provided 

 with a minute lateral aperture, which prevents the com- 

 plete shutting off of the gas supply. II. illustrates the 

 method of introducing the mercury ; and in III. the 

 regulator is provided with a metal case for protection. 



(M) INOCULATING AND DISSECTING INSTRUMENTS AND 

 APPARATUS IN COMMON USE. 



Mouse Cages. As mice are the animals most 

 frequently employed for experimental purposes, 

 mouse cages have been especially introduced, con- 

 sisting simply of a cylindrical glass jar with a 

 weighted wire cover. 



Dressing-case. A small surgical dressing- 

 case, with its usual accessories forceps, knives, 

 small straight and curved scissors, needles, silk, 

 and so forth will serve for most purposes. 



Pravaz' Syringe. Koch's modification of 

 Pravaz' syringe admits of sterilisation by exposure 

 to 150 C. for a couple of hours. 



Special Instruments and Material. Instru- 

 ments required for special operations and the 

 materials necessary for strict antiseptic precautions 

 need not be detailed here.* 



Dissecting Boards. Slabs of wood in various 

 sizes, or gutta percha trays, provided with large- 

 headed pins, are employed for ordinary purposes. 



Dissecting Case. A dissecting case fitted with 

 scalpels, scissors, hooks, etc., should be reserved 

 entirely for post-mortem examinations. 



* Vide Cheyne, Antiseptic Siirgery. 1882. 



