Cutaneous Tuberculin Test. 



585 



opposite thin fold (Fig. 94). In some animals a small hemorrhage 

 occurs at the point of inoculation. As a rule the overlying epidermis 

 dries up into a brown crust or scab. 



A swelling appearing immediately after the injection of the tuber- 

 culin but disappearing after a few hours and which, according to 

 Vallee is due to glycerin and salts contained in the tuberculin must 

 not be regarded as a positive reaction. 



Lignieres as well as Roemer and Joseph inject the tuberculin on 

 the side of the neck and as near as possible to the cutis. In this case 

 a positive reaction consists in the appearance, beginning on the following 

 day, of a painful edematous swelling around the point of inoculation. 



Fig. 94. Intradermal Tuberculin Reaction. Edematous swelling of the right anal 

 fold following injection of 0.1 cc. of 50% tuberculin into the tissue of the cutis. 



For an objective determination of a reaction the thickness of a fold of 

 skin about 5 cm. wide is accurately measured by means of micrometer 

 calipers immediately before, and then again three or four days after 

 the injection of the tuberculin at that point. If, during that tunc 

 the fold has increased in thickness to the extent of 0.4 cm. or more, the 

 reaction is to be regarded as positive, if the increase is only 0.2 to 0.3 

 cm. the reaction is to be looked upon as doubtful and the test should 

 be repeated with 0.1 cc. of concentrated tuberculin applied on the 

 opposite side of the neck. 



By means of their method (0.1-0.2 cc. of 10% tuberculin) Moussu and 

 Mantoux obtained in 70 head of cattle reactions corresponding in all respects 



