( 085 ) 

 It remains to introdnce tlie value of y.\ According to the defini- 

 tion of this quantity, it is ~ jKp^ — 1), instead of wliich Ave may take 



o 



" //, hecause p is a very large number. In this way (44) changes info 



o 



A^r^ d^ (45) 



We may finally determine the coefticient k' by remarking that 

 (45), integrated from — oo to -j- oo , must necessarily give 1. This 

 requires that 





so that our result becomes 



2jr 



Microbiology. — ''Tlie (/eccnn/wsition of ccllulos-e by alTobic micro- 

 organisms.'' By G. VAN Iterson Jr. (Communicated by Prof. 

 M. W. Beijerinck). 



(Communicated at the meeting March 28, 1903). 



When we introduce into the soil or into natural waters substances 

 consisting of cellulose, such as linen, cotton or paper, it will be 

 seen, that the greater part comparatively soon disappears, whilst 

 the cellulose derived from the continually falling dead leaves aiul 

 other parts of plants is also soon destroyed under natural conditions 

 either totally or partly. It is also a known fact that the layer of 

 humus in the primeval forests has a limited thickness, the decrease 

 l)eing just compensated by the increase caused by the falling of 

 the leaves. Investigation shows that the cellulose, although chemi- 

 cally so stable, is decomposed by micro-organisms. The observations 



by MiTSCHERLICH ^), POPOFF '^) , VAN TjEGHEM ') , TaPPEINER ^), VAN 



1) Ueber die Zusammensetzung der Wand der Pflanzenzelle, Monatslier. d. Berl. 

 Akad., 1850, p. 102. 



3) Ueber Sumpfgasgahrung, Archiv. f. ges. Physiol., 1875, Bd. 10, S. 118. 



■'') Sur le bacillus amylobacter et son role dans la putrefaction des tissus végétaux, 

 G. R. t. 88, 1879, p. 88. — Identité du bacillus amylobacter et du vibrion buly- 

 rique de M. Pasteur, C. Pv. t. 89, 1879, p. 5. 



^) Ueber Celluloseverdauung, Ber. d. d. ch. G. Bd. 15, 1882, S. 999. — Ueber 

 Gellulosegahrungen, Ber. d. d. ch. G. Bd. 16, 1883, S. 1734. — Ueber die Sumpf- 

 gasgiihrung im Schlamme der Teiche, Sümpfe u. Kloaken, Ber. d. d. ch. G. Bd. 

 16, 1883, S. 1740. 



