CHAPTER V. 

 WHOOPING-COUGH. 



IT is only recently that the bacteriology of whooping- 

 cough has begun to assume definiteness, and even yet 

 there is no certainty that any of the various described 

 bacteria play any specific part in its etiology. In all 

 diseases of the respiratory apparatus the discharges are 

 almost certain to be so contaminated with the nasal and 

 oral bacteria as to make the isolation from them of a 

 single probably specific organism a matter of difficulty, 

 and its original recognition a matter of genius. 



Of historical interest are the researches and observa- 

 tions of Deichler, KnrlofF, Szemetzchenko, Cohn, Neu- 

 mann, Ritter and Afanassiew. Those of Kurloff and 

 Afanassiew are of especial importance because they opened 

 the way for the recent studies of Koplik l and those of 

 Czaplewski and Hensel. 2 Koplik and Czaplewski and 

 Hensel worked entirely independently of each other, and 

 while the bacterium studied by the former differs in 

 several points from that of the latter, Czaplewski and 

 Hensel have claimed to see in Koplik's work a confirma- 

 tion of their own. 



Koplik studied 16 cases of whooping-cough. The 

 sputum was collected in sterile Petri dishes, in which it 

 was allowed to stand for an hour or so in order that it 

 should break up into mucous fragments. 



When the clear viscid expectoration from uncompli- 

 cated cases of whooping-cough is allowed to stand for an 



I Centralbl. f. Bakt. u. Parasitenk., Sept. 15, 1897, xxii., Nos. 8 and 9, 

 p. 222. 



II Deutsche med. Woch., 1897, No. 57, p. 586, and Centralbl. f. Bakt. u. 

 Parasitenk., Dec. 22, 1897, xxii., Nos. 22, 23, p. 641. 



