EXPERIMENT STATION BULLETINS. 



291 



XX. ACTION OF 



HYDROGEN UPON THE DEVELOPMENT OP SPECIFIC MICRO- 

 ORGANISMS. 



It is pertinent to place against the previous work, the action of hydrogen upon the 

 micro-organisms which have been studied thus far. The purpose of this is, not only 

 to check the previous work but to indicate whether the results obtained thus far are 

 entirely due to carbon dioxide present, or to what may be regarded as the anaerobic 

 conditions. To speak of these conditions without defining exactly their nature must. 

 of course, leave us somewhat in darkness, but this must always remain so until more 

 is known concerning anaerobic life. It is a common practice to use hydrogen in securing 

 anaerobic conditions; for this reason, a comparison of hydrogen with carbon dioxide 

 may be of interest. The methods were the same as in the previous work. Table Will 

 tabulates the results. 



TABLE XVIII. 



ACTION OF HYDROGEN UPON THE DEVELOPMENT OF SPECIFIC MICROORGANISMS. 



119. 

 120. 

 121. 

 122. 

 123. 

 124. 

 126. 

 127. 

 128. 

 129. 

 130. 

 131. 

 132. 

 133. 

 134. 



No. of micro-organism. 



Plates developed in 

 hydrogen. 



Plates developed in 

 air as check. 



Growth. 



n. g. 



r- g. 

 v. g. 



r- g- 

 n. g. 



r- g- 

 n. g. 

 n. g. 

 r. g. 



No. of 

 colonies. 



Growth. 



v. g. 



1,500 v. g. 



4,592 V. g. 



3,200 v. g. 



(1,4(10 v. g. 



v. g- 



v. g. 



3,900 



v. g- 



No. of 

 colonies. 



1,200 

 1,540 

 5.160 

 4.4*0 

 1,158 

 9,600 

 3,100 

 720 

 4,570 



r- g. 

 r. g- 

 n. g. 

 n. g. 

 v- g- 



1,500 

 1,300 



1,680 



V. g- 



v. g. 

 v. g. 

 v. g. 

 v. g. 



4,400 

 1.580 

 1,120 



1,440 

 1.740 



From this table there will be found a very close similarity in the results as found 

 In the case of carbon dioxide. The differences are mi alight thai in a general conclusion 

 they may be overlooked. 



