TUBERCULOSIS. 237 



of mutual compensation is set up, and to this is due the fact 

 that the growth of isolated bacilli is so remarkably restricted, 

 as for example, in the case of lupus, in scrofulous glands, &c. 

 In such cases the necrosis extends only over a part of the 

 cell, which then, in its further growth, assumes the peculiar 

 form of a giant cell. I thus follow in this statement of my 

 views the explanation of the growth of giant cells first given 

 by Weigert. Now if the necrosis-producing substance were 

 artificially added to that contained in the tissue surrounding 

 the bacillus, then the necrosis would extend further, and 

 thus the conditions of nutrition of the bacillus would 

 become much more unfavourable than is usually the case. 

 Then, not only would the more completely necrosed tissues 

 disintegrate, slough, and where this is possible take with 

 them the enclosed bacilli, carrying them outside the body, 

 but the growth of the bacilli would also be interfered with 

 to such an extent that they would die off much sooner than 

 they do under ordinary conditions. It is in calling forth 

 such changes that, to my mind, the action of the remedy 

 seeems to consist. It contains a certain amount of the 

 necrosis-producing substance, of which a correspondingly 

 large dose has a deleterious influence even in healthy 

 persons on certain elements of the tissues, probably on the 

 white blood corpuscles or cells closely related to them, thus 

 giving rise to the fever and the whole peculiar complex of 

 symptoms that supervenes. In tuberculous persons a much 

 smaller quantity suffices to cause, at certain spots i.e., 

 wherever tubercle bacilli vegetate, and have already impreg- 

 nated their surroundings with the necrosis-producing sub- 

 stance a more or less extended necrosis of cells with the 

 production of the accompanying conditions that affect the 

 entire organism. In this way it is possible to explain at 

 least for the present in a provisional manner, the specific 

 influence which the remedy, in- certain well-recognized doses, 

 exercises on tuberculous tissue, as well as the possibility of 

 increasing the doses in so remarkable a fashion, and, finally, 

 to explain the curative effect which the remedy undoubtedly 

 exerts where the conditions are at all favourable for its 

 exhibition." 



The substance to which the name of Tuberculin has been given 

 has been analyzed, and is found to be "a syrupy, slightly foaming 

 liquid (sp. gr. 1015 ?) of brown sherry colour, its aqueous solutions 



