071 Sal Nitrum and Nitro- Aerial Spirit iii 



are brought to due maturity by the aid of nitro-aerial 

 spirit, as has been shown elsewhere. 



Further, in all the internal movements which take 

 place in the bodies of animals, as in the digestion of 

 food, and also in that most intense effervescence which 

 gives rise to muscular contraction, nitro-aerial particles 

 play the chief part, as I shall attempt to show in the 

 fourth treatise. 



I 



CHAPTER IX 



WHETHER AIR CAN BE GENERATED ANEW 



Now that we have shown above in how many ways 

 air is impaired, it will not be out of place to inquire 

 whether it can be generated anew. On this point I 

 shall introduce an experiment not very unlike the 

 one by the illustrious Boyle already referred to. 



Let, then, spirit of nitre and spring water, mixed in 

 equal quantities, be placed in a glass vessel of sufficient 

 size. Then let a small glass be so placed under the 

 mixture that it shall be completely filled with the 

 liquid. This done, let two or three globules of iron 

 be placed at the mouth of this glass, and let it lie 

 inverted at the bottom of the other, as is shown in 

 Plate v.. Fig. 3, care being taken that these globules 

 do not fall out of the glass, and to secure this let the 

 mouth of this glass be closed with the finger or in any 

 other way, until it rests at the bottom of the other 

 glass. These preparations made, the acid menstruum 

 will, after a short time, corrode the iron globules and 

 effervesce conspicuously with them, and the exhala- 



