MARAGLIANO'S TUBERCULIN 329 



Tuberculin TO is not altered by the addition of 50 per cent, of glycerin : 

 its properties are almost identical with those of ordinary tuberculin and its 

 immunizing properties are nil or very little marked. 



Tuberculin TR gives a flocculent, white precipitate on the addition of 50 

 per cent, of glycerin. Its characters are unaltered by the addition of 20 per 

 cent, of glycerin which, on the other hand, preserves it. 



According to Koch tuberculin TR has distinct immunizing properties. 

 Repeated inoculation of small doses into the human subject confers an im- 

 munity against ordinary tuberculin and TO, as well as against itself. These 

 statements have not been confirmed (Bounhiol) ; tuberculin TR, whatever 

 Koch may have said, appears to have no power of arresting tuberculosis. 

 In tuberculous persons, a reaction similar to that produced by ordinary 

 tuberculin occurs but very inconstantly. It appears to be less dangerous 

 than ordinary tuberculin, but, on account of the irregularity of its effects, 

 it cannot be used for purposes of diagnosis. 



D. Maragliano's tuberculin. 



This is a watery tuberculin obtained by maceration of tubercle bacilli. 

 Recover the bacilli from a glycerin-broth culture, add to them a volume 

 of distilled water equal to the volume of the culture' fluid and heat to a 

 temperature of 95-100 C. for 50 hours or so. Then evaporate on a water 

 bath to one-tenth its original volume and filter through filter paper. 



The filtrate has the same properties as Koch's old tuberculin and is said 

 to possess vaccinating properties. Doses of 5 c.c. are fatal to healthy guinea- 

 pigs weighing 500 grams. Tuberculous guinea-pigs succumb to the inocula- 

 tion of 0'10-0'20 c.c. of this tuberculin. 



When precipitated with alcohol, Maragliano's tuberculin yields a powder 

 which kills guinea-pigs in doses equivalent to 25 ,o 00 th of their weight and 

 rabbits in amounts corresponding to 3a ,o 00 th of their weight. 



E. Toxalbumin. 



The different toxic products which have just been studied are contained 

 within the bacilli endotoxins and to extract them the bacilli have to be 

 killed by heat or destroyed by trituration. 



Maragliano, Bezancon and Gouger have shown that the tubercle bacillus 

 produces a diffusible toxin which passes into the medium in which the bacilli 

 are growing. This toxin is of the nature of a toxalbumin : it is destroyed 

 by heating it to 100 C. and by prolonged exposure to light. It is prepared 

 by filtering a glycerin-broth culture through porcelain and concentrating the 

 filtrate to one-tenth its original volume in vacuo at 55 C. 



The product differs absolutely from the tuberculins : it is more toxic than 

 the latter and inoculated into animals it never produces a rise of temperature 

 even in non-fatal doses : in fatal doses the animals die with a sub-normal 

 temperature. 



Denys uses a porcelain-filtered glycerin-broth culture of the tubercle bacillus 

 in the treatment of tuberculosis. 



Beraneck prepares a toxin-broth by growing the tubercle bacillus in a 

 maceration of veal made in the cold to which 0*5 per cent, salt and 5 per 

 cent, glycerin are added before sterilization. .By the time that the surface 

 is covered with a pellicle, the medium, originally alkaline, has become acid. 

 It is then made alkaline with lime water, filtered through a Chamberland 

 bougie, and the filtrate evaporated in vacuo to one-tenth its original volume. 



Beraneck recommends for the treatment of tuberculosis the use of this toxin broth 

 diluted with an equal volume of an acid extract of the bodies of bacilli containing 



