78 



positive microscopic findings in the 3 groups respectively. As 

 we cannot suppose that the method of collecting sputa in the 

 summer epidemic will explain the scanty positive findings at 

 that ..time,, the. figures point strongly to -the. fact, that Pfeiffer's 

 bacillus has really increased Jn .distribution between the first 

 and second epidemic. . u . . . . a ... 



(c). The epidemic jn 1920. 



an the period from 28. I— 9. III. 1020 Pfeiffer's bacillus 

 was cultivated from 4 out of 15 sputa, and from the pneumo- 

 nic lung tissue of 6 out of 59 autopsies. In 20 of these au- 

 topsies cultivations were also made, from 1 the pleural exudate 

 without Pfeiffer's bacillus being found once. 



These investigations were chiefly made in order to obtain 

 some samples of Pfeiffer's bacillus from this stage of the "epidemic, 

 and I was therefore not present at the autopsies, but the pieces 

 of dung tissue and pleural exudates were' sent to me. As a 

 considerably longer time ' elapsed "than in the case of the pre- 

 vious investigations; before the cultures could be made one 

 cannot expect to draw any conclusion from the relatively scanty 

 positive findings as to whether Pfeiffer's bacillus occurred less 

 frequently in this epidemic than in the previous one. 



(d). The epidemic in 1922. 



Immediately after the rather sudden outbreak of the epi- 

 demic in the garrison of Copenhagen, I examined (on the 

 7. I. and & I) 38 soldiers with uncomplicated influenza, for 

 Pfeiffer's bacillus at the military hospital. 



The examinations were made in 2 wards, which had been 

 empty till the day of the examination, so that a hospital infection 

 with Pfeiffer's bacillus must be regarded as excluded. On this 

 occasion only cultures from the throat were examined, not 

 sputa. After the specimen was taken the inoculation rod was 

 put in a test tube and transferred to a portable incubator the 

 temperature of which was kept at 32 — 35°. 



This incubator was constructed of two glass cylinders (jam jars), 

 one inserted inside the other. In the intervening space between the 

 cylinders melted zinc nitrate (Zn(N0 3 ) 2 , 6H 2 0) was poured, a salt 

 the melting point of which is about 35°. The outer cylinder was 

 surrounded by an insulating cOver of newspaper etc. On solidifi- 



