PASTEUR, KOCH, AND OTHERS 303 



the septic property of the atmosphere depended, not on oxy- 

 gen or any gaseous constituent, but on minute organisms 

 suspended in it, which owed their energy to their vitality, it 

 occurred to me that decomposition in the injured part might 

 be avoided without excluding the air, by applying as a dress- 

 ing some material capable of destroying the life of the float- 

 ing particles." At first he used carbolic acid for this purpose. 

 "The wards of which he had charge in the Glasgow Infirm- 

 ary were especially affected by gangrene, but in a short time 

 became the healthiest in the world; while other wards sepa- 

 rated by a passageway retained their infection." The 

 method of Lister has been universally adopted, and at the 

 same time has been greatly extended and improved. 



The question of immunity, i.e., the reason why after hav- 

 ing had certain contagious diseases one is rendered immune, 

 is of very great interest, but is of medical bearing, and 

 therefore is not dealt with here. 



Schaudinn. During recent years remarkable advances 

 have been made in the study of protozoa that are connected 

 with human and animal diseases, and no single observer has 

 contributed more eminently to these advances than Fritz 

 Robert Schaudinn, 1871-1906 (Fig. 940). He made impor- 

 tant discoveries and opened up new lines of investigation 

 that are full of promise. After studies on f oramenif era ( 1 894) , 

 and nuclear division in other protozoa (1896), he was drawn 

 to the study of pathogenic protozoa, the life history of which 

 he followed with conspicuous success. After unravelling 

 the complexities of the life-cycle in certain coccidia, parasitic 

 in the mole, he traced in the human blood corpuscles the 

 different stages of the carriers of malaria. 



In 1901, under the auspices of the Imperial Health Bureau 

 (Kaiserl-Gesundheitsamtes) of Berlin, he went to the station 

 at Rovigno, and thereafter to the end of his life, he devoted 



