PEEPAEATION OF THE MATEKIAl. 215 



tread the bed lightly, as it is made up, thus lessening 

 the Hahility of burning in the center. In perhaps three 

 or four days, the mass will again warm up, and before it 

 has had time to burn, it should be again turned over ; 

 the turning should be repeated generally from three to 

 five times. 



The working oyer is for the purpose of securing a 

 regular, even heat throughout the pile, and of prevent- 

 ing "fire-fanging." As the mass warms up, the rapidity 

 of fermentation can be checked by firmly tramping the 

 pile, as it is worked over. The turning should be kept 

 up until the violent heat is over, and the strong offen- 

 sive odor has been dissipated. When properly purified 

 and sweetened, the bed should be a homogeneous mass 

 of a warm brown color, and with a "sweet," agreeable 

 and slightly pungent odor. If properly prepared, the 

 material should have a greasy appearance, but should 

 not be so moisb as to allow even a drop of water to be 

 squeezed out. Most growers add to the manure about 

 one-fourth its bulk of loam, the amount varying with 

 the freshness of the manure, more being used when it is 

 fresh than if decomposed. The addition of the loam is 

 thought to benefit by hindering decomposition and thus 

 extending the productiveness of the bed ; it also serves 

 to retain the ammonia and in this way may be of value, 

 although its use is not regarded as necessary, and it is 

 entirely dispensed with by some growers. 



The loam is generally obtained from land that las 

 not been pastured for two years at least, as it otherwise 

 might contain worthless fungi that would prove tivable- 

 some, although by some of the most successful growers 

 this precaution is considered unnecessary. The manure 

 may be mixed with the loam, at the time it is first piled 

 up, at any time during its preparation, or when ready to 

 be placed in the mushroom bed, but an excellent plan is 

 to use it to cover the pile, after it has been worked over 



