iSlO Spontaneous Changes of Organized Matter. [April, 



so effectually, without endangering the interests of man — or where 

 could they be exerted at all, except in high places, and in the re- 

 mote and sometimes inaccessible fields of snow? 



ON THE SPONTANEOUS CHANGES WHICH ORGAN- 

 IZED MATTER UNDERGOES WHEN EXPOSED TO 

 THE ACTION OF CHEMICAL AND PHYSICAL FORCES. 



We have had so many occasions for speaking of the organic 

 acids and other products derived from organic matter, that we 

 deem it necessary to say a few words upon these products. The 

 woody tissues of dead plants give origin to a class of bodies 

 which were formerly known under the name of Ulmine, but 

 which are now known to consist of several distinct substances, 

 differing both in composition and in their properties. To form 

 ulmine it is only necessary that wood should be exposed in con- 

 tact with air and moisture. Under these circumstances, however, 

 both ulmic and ulraic acid is formed. Their names imply that 

 they were derived from the woody tissues of the elm. The latter 

 is insoluble in water or alcohol, but is soluble in alkaline solu- 

 tions, and in its natural state contains ammonia, which may be 

 expelled by caustic potash, when the acid itself is decomposed. 

 The formation of these bodies during the decay of wood results 

 from the absorption of oxygen and the evolution of carbonic acid 

 and water. They are both brown uncrystalizable bodies, and re- 

 semble vegetable extracts. 



The theory of the formation of these bodies, is analagous to 

 that of fermentation; for it is necessary in order they may be 

 formed, that an azotized substance should be present, which being 

 first decomposed communicates the action to the woody fibre, and 

 the albuminous juices which exist in the vessels act as a ferment. 

 This view is supported by the fact that~ any process or method 

 which prevents fermentation in any instance, prevents also the 

 decay of wood; for, notwithstanding wood is exposed to the ac- 

 tion of oxygen and water for a long time, its rotting is prevented 

 when it is saturated with corrosive sublimate or pyroligneous acid, 



