TUBERCULINE. 171 



liquid, and treated the residual bacilli in the same way successively at 50, 

 60, &c., up to 100 C. The different extracts were then united and mixed 

 with culture fluid, and the whole evaporated at 37 C. in vacuo and filtered 

 through porcelain. In this way he obtained a mixture of all the products 

 of the tubercle bacilli, including both the toxines destroyed by heat as 

 well as the hot-water extracts, with the proteins. He claimed to have 

 produced therapeutic results by means of this mixture. It is obvious that 

 such mixtures as this cannot advance our theoretical knowledge. 



Subsequently KocH, 1 in a later research, published a new 

 method of making tuberculine preparations. 



He triturated O'l grm. of the absolutely dry tubercle bacilli in an agate 

 mortar with a solution of 0*5 grm. of phenol and 0*85 grm. of sodium 

 chloride in 100 c.c. of water, a few drops being used at first, and then 

 more and more of the liquid until the total amounted to 100 c.c. The 

 mixture was then whirled for six minutes in a centrifugal machine, 

 decanted from the deposit, and diluted with ten times its volume of the 

 solution, so that eventually the liquid contained in a litre the extract from 

 0*1 grm. of tubercle bacilli. 



This liquid was rendered turbid by the addition of agglutinating serum. 

 By itself it also served the purpose of diagnosis. 



The question of the nature of the poisons of the tubercle 

 bacillus was thoroughly studied by RUPPEL. 2 He found, first 

 of all, that the nitrates were absolutely non-specific, and, with 

 the exception of albumoses, chiefly deuteroalbumose, was unable 

 to discover anything toxic in them. Nor was he more successful 

 in his attempts to isolate any specific poison from the bacilli by 

 extraction. This really gives a definite answer in the negative 

 to the question whether there exists a soluble specific toxine of 

 the nature of diphtheria toxine. 



On the other hand, he isolated from the crushed bacilli two 

 poisonous substances viz., a nucleic acid containing 9*42 per 

 cent, of phosphorus, tuberculinic acid, and also a protamine, 

 which he recognised as such by its being precipitated with 

 picric acid, and termed tuber cidosamine. The proportion of the 

 finely-divided bacilli dissolved after treatment in a centrifugal 

 machine amounted to 50 per cent. The solution gave no proteid 

 reactions and probably contained only a compound of the nucleic 

 acid with the protamine. According to NEUFELD, S however, 

 the action of tuberculosamine is absolutely non-specific and v. 

 Lingelsheim's method of valuation (vide supra) cannot be used. 



1 Koch, "Ueb. d. Agglut. d. Tuberkelbacillen, " Deutsch. med. Woch., 

 1901, 829. 



2 Ruppel, "Zur Chemie der Tuberkelbazillen," Z. f. phys. Chem., xxvi., 

 218, 1898. 



3 Neufeld, "Zur Werthbestimmung der Tuberkulosepraparate," Deutsch. 

 med. Woch., 1899, 13. 



