46 Mayow 



Further, with respect to the heat which arises in 

 solid bodies when rubbed together, it is probably 

 due to nitro-aerial particles residing in those bodies 

 and thrown into motion by vehement rubbing ; for 

 the more solid kinds of wood appear to be rich in 

 nitrous particles as has been shown above. Nay, 

 that solidity and even rigidity are caused by nitro- 

 aerial particles I shall endeavour to show below. 

 Lastly, with respect to blood, and quicklime, and 

 other things of the same kind, it will be established 

 below that their heat is produced by nitro-aerial 

 spirit. 



Lastly, we remark with regard to fermentation in 

 general that nitro-aerial spirit will not ferment with 

 sulphur unless the sulphur is to some extent fixed. 

 For liquids which contain sulphureous particles 

 highly exalted, such as spirit of wine, never effer- 

 vesce even though exposed to the warmest air, while 

 juice expressed from grapes and new ale (in which 

 the sulphureous particles have not yet attained to 

 vigour and inflammabiHty) ferment of themselves. 

 And indeed it is the saHne particles in union with 

 the sulphureous which seem to be the cause of 

 everything becoming acid in fermentation as we 

 have indicated above. For the saline particles which 

 were previously wrapped up in the sulphureous 

 particles, are afterwards by fermentation set free 

 from their fellowship, and besides brought into a 

 fluid condition as described above. 



But although nitro-aerial spirit does not attack 

 highly exalted sulphureous particles, yet sulphureous 

 particles, when in the greatest vigour and agitation, 

 attack nitro-aerial spirit and throw it into a very 

 swift and fiery motion. For, as it is necessary that 

 sulphur should be to some extent in a state of fixation 



