Historical sketch on Immunity 513 



elements of the organ in question. Inflammation, therefore, is 

 regarded by Buchner as a salutary reaction, which acts, not directly [536] 

 on the exciting morbific cause, but through the mediation of the 

 specific cells of the organs. This theory of immunity led Buchner to 

 propose arsenical treatment as a remedy against microbial disease, 

 because arsenic is, of all drugs, the one capable of setting up the 

 greatest inflammatory reaction. 



Another German observer, Grawitz 1 , proposes a theory of acquired 

 immunity, according to which a first attack of an infective disease 

 sets up "the adaptation of the cells to the power of energetic 

 assimilation of the fungi." This reinforced adaptation is transmitted 

 to the descendants of the cells which have acquired it, and for 

 that reason the immunity may persist for months, and even years. 

 Grawitz attempted to base his views on experiments on the acquired 

 immunity against the fungus of the lily of the valley, but Loeffler 2 

 soon demonstrated that this thesis could not be maintained, and that 

 the immunity assumed by Grawitz did not, in reality, exist. 



It will be seen that all the theories summarised above are marked 

 by their vague character and want of precision ; this is not at all 

 astonishing when we take into consideration the very imperfect 

 knowledge of the phenomena of immunity. It is evident that if we 

 wish to gain a satisfactory idea of the mechanism of the resistance 

 of the animal body against pathogenic micro-organisms, we must 

 inform ourselves as to the modifications which take place in the 

 organs and tissues at the time of the acquisition of the immunity, 

 and also find out what becomes of the micro-organisms in a refractory 

 animal. 



We have seen that Chauveau demonstrated that anthrax bacilli 

 when injected into the vessels of Algerian sheep disappear, but he 

 was unable to say anything as to the way in which this disappearance 

 was brought about in nature. Buchner accepted the reinforced 

 resistance of inflamed organs without being able to describe the 

 phenomena which manifest themselves during the inflammation of 

 tissues invaded by the pathogenic micro-organisms. 



Independently of these theoretical and rather speculative views 

 on immunity, there has been an addition to our scientific assets of 

 fairly exact data on the relation of certain pathogenic organisms to 

 the organs and tissues of susceptible or refractory animals. When, as 



1 Virchow's Archiv, 1881, Bd. LXXXIV, S. 87. 



2 Mitth. a. d. k. Gsndhtsamte, Berlin, 1881, Bd. I, S. 134. 



R 33 



