MISSOURI BOTANICAL GARDEN. 



erties have been attributed to its humus acids. Thus 

 Stutzer and Burri * killed cholera germs in a quarter of an 

 hour with a decoction of peat. Lyell f speaks of the re- 

 mains of animals and men, which had been perfectly pre- 

 served for many years in peat bogs. Kerner von Marilaun J 

 holds that the preservation of plant parts is brought about 

 in moors by humus acids. " The dead plants are saturated 

 with these acids and are not resolved into carbon dioxide, 

 ammonia and water, but preserve their form and weight. 

 The rapidity of decay varies inversely as the quantity 

 of compounds of humus acids present." Also " the fact 

 that fossil remains of Equisetums, Lycopodiums and 

 Cycads . . . have reached us in such good condition, 

 is explained by the presence of humus acids which are 

 found so universally in peat. Ganong || points out that 

 the scarcity of nitrogen in peat bogs is due to the absence of 

 bacteria * ' caused doubtless by an actively antiseptic quality 

 of the bog water." Trees and stumps have often been 

 found in bogs perfectly preserved. Lyell (1. c.) speaks of 

 tree-trunks dug out of Irish bogs and used for masts, also 

 of white cedar logs in New England bogs. 1f Other 

 instances might be mentioned, but these will suffice to 

 show that the humus compounds have antiseptic and 

 preservative properties. 



In the heartwood of the cypress one finds the wood 

 substance being split up and destroyed. The decomposi- 

 tion stops after a time, and the fungus mycelium, which at 



* Stutzer A., u R. Burri. Untersuchungen iiber die Einwirkung von 

 Torfmull . . . auf die Abtotung der Cholerabakterien. (Zeits. f. Hyg. 

 u. Inf. Krank. U : 453. 1893.) 



t Lyell, Sir Chas. Principles of geology 722. 



| Kerner von Marilaun, A. The natural history of plants 1 : 262 (Eng, 

 edit, by F. W. Oliver). 1894. 



Kerner von Marilaun. 1. c. 2 : 612. 



|| Ganong, W. F. Upon raised peat bogs in the province of New 

 Brunswick. (Trans. Roy. Soc. Canada ii. 3 : 131. 1897.) 



f Lyell, Sir Chas. A second visit to the United States 33. 1850. 

 36 



