554 . Stall-Manure and Straw. [December, 



these offensive gasses and vapors combine with more oxygen, and 

 now undergo complete putrefaction or combustion; and the products 

 so eliminated are destitute of smell. This kind of decomposition, 

 which is most analagous to complete combustion, and, like this, takes 

 place with abundant air and a proper draught, is called decay. 



Why putrid drainings, and putrid manures, when applied to mead- 

 ows or fields, diffuse at first a powerful odor, but lose this smell a 

 short time afterwards, is therefore very simply explained: they lose 

 their odor, because they can now absorb oxygen in any quantity from 

 the air, and from the process of putrefaction can make a further 

 transition into that of decay. 



If moist vegetable or animal tissues lie in a room from which the 

 air is entirely or partially excluded — for instance in a cellar which 

 has no ventilation, or in a chest, etc. — then in the undisturbed, 

 damp air, a decomposition takes place, consisting partly of putrefac- 

 tion, partly of decay — the well-known process of moldering, recog- 

 nized mainly by its close smell, and simultaneous production of 

 mold, fungi, and spongy excrescences. By the addition of water, 

 this kind of decomposition may be converted into putrefaction \ by 

 the introduction of a current of air, into decay ; or, lastly, it may 

 be brought entirely to a close, if by means of ventilation, all moist- 

 ure is evaporated, and the decaying body becomes completely dry. 



In common conversation, the words " putrefaction," "moldering," 

 and "decay," are deemed synonymous in meaning, and the one or 

 the other of these words is used at the pleasure of the speaker to 

 designate the changes under our consideration. In the majority of 

 cases, it is indeed a matter of indifference, and in a strict sense not 

 at all incorrect, inasmuch as in most decomposing bodies all three 

 processes are of simultaneous occurrence ; externally, with free ac- 

 cess of air, decay ; in the midst, between both, moldering. Here, 

 however, reference must be made to a distinction in these processes, 

 the knowledge .of which is important in a practical respect; we mean, 

 the fact that we have to consider putrefying and moldering sub- 

 stances only as a half-prepared or half-finished nutriment for the 

 plants in cultivation; decaying substances, on the contrary, as a fully 

 prepared or perfected vegetable nutrient. By the putrefaction and 

 moldering of manure, its constituent elements are put in training 

 for a brisk decay, but by decay are first transferred to those combi- 

 nations which are consumed by plants for their nutrition. Putre- 

 faction and moldering may be compared, in tbis respect, to the 



