306 AGRICULTURAL BACTERIOLOGY. 



pose is in use in some countries though not much known in 

 America. It consists of a process in some respects similar to 

 ensiling, but differing in certain important points and resulting 

 in a somewhat different product. As commonly employed 

 the method is as follows : 



Pits are prepared from 40 to 80 inches deep, and from So to 

 1 20 inches wide. The material to be treated is tightly packed 

 in these pits and covered with a layer of chaff, over which is 

 placed a thick layer of soil. Upon the whole is placed a 

 layer of boards, which are weighted with stones sufficient to 

 produce a pressure of nearly 2,000 pounds per square yard. 

 In such a compactly pressed mass it is hardly possible for 

 oxygen to enter, and the respiratory changes, so important in 

 the silage, hardly occur. There is a slight rise in temperature 

 but rarely over 95 F., which temperature is reached in a little 

 over two weeks. After this the temperature falls. The changes 

 that take place in the material have not been much studied. 

 There is a very marked loss of material, amounting in some 

 cases to a quarter of the weight of the dry substance. The 

 loss is chiefly in the carbonaceous materials, the woody fibers, 

 and also in the albuminoids. In some instances as much as 

 60 per cent, of the albuminoids is lost in the process of fer- 

 mentation. It is also a fact that the development of acids 

 is large, especially the development of volatile acids, which 

 give the material a strong acid smell and taste. 



It has been assumed, without proof, that in this preparation 

 of sour fodder, we have a process in which bacteria are chiefly 

 concerned and that the acid-forming bacteria are the important 

 agents. Such is a natural supposition from the slow develop- 

 ment of heat, and the subsequent large development of acid. 

 But the demonstration of the large agency of other processes, 

 in the formation of ordinary silage, throws the whole question 

 open to debate, and suggests that here too other phenomena 

 besides the growth of microorganisms may be concerned. 



