On Sal Nitnim and Nitro- Aerial Spirit 43 



excited, and this must be supposed to result from 

 the motion of nitro-aerial particles, as will be shown 

 immediately. How great moreover is the resem- 

 blance and affinity between fire and all other fer- 

 mentations will appear from what follows. 



With regard to fire, it is to be noted that for the 

 burning of things, it is necessary that nitro-aerial 

 particles should either be already in the burning 

 substance or be supplied from the air. Gunpowder 

 burns very readily on account of the nitro-aerial 

 particles it contains ; plants burn partly from the 

 nitro-aerial particles they contain, and partly from 

 such as come from the air ; but sulphureous matter, 

 pure and simple, can only be ignited by nitro-aerial 

 particles supplied by the air. 



And, just as for the production of fire, so also for 

 exciting fermentations in plants, both sulphureous 

 and nitro-aerial particles must either exist in the 

 things to be fermented or be supplied from without. 

 The juice expressed from plants, such as the must 

 of wine or of apples and the like, effervesces on 

 account of the nitro-aerial and sulphureous particles 

 which it contains. For we have shown above that 

 nitrous salts and therefore also nitro-aerial particles 

 are contained in most plants, though, at the same 

 time, the nitro-aerial spirit supplied by the air con- 

 tributes much to the fermentation of these liquids, 

 for very warm weather intensifies the action in no 

 small degree. Further, that the fermentation of the 

 aforesaid liquids, as also of all things whatsoever, is 

 due to the mutual agitation of nitro-aerial and 

 saline-sulphureous particles, is evident from the fact 

 that liquids of this kind, and indeed nearly every 

 thing, become sour in fermenting ; for it has been 

 shown above that acidity is caused by the action of 



