137 



a practical point of view this has experimentally proved the 

 most suitable solution, as a stronger T solution is too deeply 

 brown-coloured and a weaker one checks too little. 



The controlling tubes 15 and 20 too, were prepared in order 

 to be able to determine more easily, in comparison with a 

 tuberculine-solution, in which dilution of the serum the fibrine 

 was absolutely no longer corroded ; so where the absolute 

 checking of the fibrine-transformation by tuberculine commenced. 

 These mixtures were placed in the incubator for 16 hours in 

 a temperature of 37 C. and then the result was examined. 

 In comparing the tubes of the first series it appeared that the 

 fibrine-transformation in serum B., obtained from a non tuber- 

 culosis, is somewhat stronger than in serum A. In the 400 

 times diluted solution of both sera fibrine had still been 

 transformed ; in serum B. however not much less than in serum 

 A. Still almost absolute checking of the fibrine transformation 

 of the 2 7o tuberculine-solution had already begun in the 100 

 times diluted solution of serum B. ; in the 200 times diluted 

 solution no more eosine had been let loose at all. In the 

 dilution of serum A it was quite different, however. In the 300 

 times diluted solution of this serum no absolute checking by the 

 T solution had even as yet arisen. So quite a difference! 



This experiment beautifully illustrates the first part of the 

 above-mentioned rule. If on the contrary, the fibrolytic power 

 of the sera to be compared mutually, is not the same, but if 

 that of non-tuberculous sera is much stronger than that of 

 tuberculous sera, quite another result will be seen. For instance: 

 From 2 patients, one healthy, the other suffering from abdominal 

 tuberculosis the sera are examined. The decisive point of the 

 fibrine-transformation of serum A. is reached when the serum is 

 1200 times diluted. With Serum B. this decisive point is already 

 reached with the 400 th dilution. Absolute checking by a 2 0/0 

 tuberculinesolution in serum A. with a solution of i : 350 ; in 

 serum B. with a solution of i : 250. Serum obtained from 

 the non-tuberculous person must now be further diluted than 

 that of the tuberculous individual. If we consider the results 

 of our preparatory researches however, this is not difficult to 

 understand. The stronger the primary peptic power of the 

 serum is, the more tuberculine will have to be added, or the 



