THE FERMENTATION OF CELLULOSE 229 



anaerobic conditions prevail, methane, hydrogen, and 

 carbon dioxide and other substances are formed. 

 Deherain and Dupont made analyses of the gases within 

 a large heap of mixed farmyard manure. Below are 

 some of the results : 



August 24, 1899 Temp. CO 2 CH 4 H NO 



Top of the heap 71 50 17.4 3.1 29.5 o 

 Middle 67 68 23.9 7.4 .7 o 



Bottom 63 49 40.8 3.9 6.0 o 



About a month later (Sept. 20 1899) 



Top of the heap 66 42.7 52.4 o 9.8 i.i 

 Middle 65 49.5 48.3 o 2.2 o 



Bottom 52 47.8 51.2 o i.o o 



Van Tieghem, Hoppe-Seyler, and the earlier workers 

 at cellulose fermentation, concluded that the chief 

 organisms concerned in the process were Bacillus amylo- 

 bacter and allied species of butyric bacteria. According 

 to Van Sen us, Bs. amylobacter works symbiotically with 

 an aerobic species in the decomposition of cellulose. 

 Certain it is that many of the butyric forms which stain 

 a blue colour with iodine are present when the cellulose 

 tissues of plants are undergoing fermentation and dis- 

 organization under anaerobic conditions, but further 

 experiments are needed to determine the particular part 

 which they play. 



The isolation of two forms of bacteria capable of 

 breaking down cellulose with the formation of methane 

 and hydrogen was accomplished by Omeliansky in 1895. 

 Pieces of filter paper and cotton wool were placed in 

 flasks of nutrient solutions containing potassium phos- 

 phate, magnesium sulphate, ammonium phosphate and 



