C 273 j 



ciples on which this may be effected have been allud- 

 ed to. 



The surface should be defended as much as pos- 

 sible from the oxygene of the atmosphere ; a compact 

 marie, or a tenacious clay, offers the best protection 

 against the air ; and before the dung is covered over, 

 or as it were, sealed up, it should be dried as much 

 as possible. If the dung is found at any time to 

 heat strongly, it should be turned over, and cooled 

 by exposure to air. 



Watering dunghills is sometimes recommended 

 for checking the progress of fermentation ; but this 

 practice is inconsistent with just chemical views. It 

 may cool the dung for a short time ; but moisture, as 

 I have before stated, is a principal agent in all proces- 

 ses of decomposition. Dry fibrous matter will never 

 ferment. Water is as necessary as air to the process ; 

 and to supply it to fermenting dung, is to supply an 

 agent which will hasten its decay. 



In all cases when dung is fermenting, there are 

 simple tests by which the rapidity of the process, and 

 consequently the injury done, may be discovered. 



If a thermometer plungedJnto the dung does not 

 rise to above 10O degrees of Fahrenheit, there is little 

 danger of much aeriform matter flying off. If the 

 temperature is higher, the dung should be immediate- 

 ly spread abroad. 



When a piece of paper moistened in muriatic 

 acid held over the steams arising from a dunghill 

 gives dense fumes, it is a certain test ? that the decom- 



N 2 



