X Contents 



Mercury and spirit are to be regarded as the same element, 

 p. 34. On sulphur, p. 35. Mercury and sulphur are 

 mutually hostile, p. 35. On salt, p. 35. On water and earth, 

 pp. 35 and 36. On the mutual action of the said elements, 

 p. 36. The aerial mercury is fixed in the embrace of salt, 

 p. 36. Sulphur freed from association with salt attains a 

 condition of volatility, p. 37. But is fixed when united with 

 it, p. 37. On the origin of vegetables, pp. 37 and 38. Why 

 nitre is especially formed in spring, p. 38. Why substances 

 containing salt and sulphur make land fertile, p. 38. Vege- 

 tables contain nitrous salt, but not purely saline salt, p. 39. 

 But by the deflagration of vegetables it becomes lixivial, p. 39. 

 Why vegetables, when calcined with a subdued flame, yield 

 more salt than otherwise, p. 39. Diuretic salts ought not to 

 be calcined with violent heat, p. 40. Why the smoke of 

 kindled coals causes suffocation, p. 40. Why fermenting 

 liquors become somewhat acid, p. 40. Why some vegetables 

 yield only a little fixed salt, p. 41. The nitre contained in 

 vegetables promotes their combustion, p. 41. On the 

 fermentation which causes the destruction of vegetables, p. 

 41. Fire is the most destructive fermentation, p. 42. There 

 is a close resemblance between fire and other fermentations 

 tending to the destruction of things, p. 43. How things are 

 corrupted by extraneous heat and moisture, p. 44. What is 

 the nature of ferments, p. 45. All heat seems to arise from 

 nitro-aerial particles set in motion, p. 45. Why things 

 become acid in fermenting, p. 46. 



CHAPTER VI.— Of Nitro-Aerial Spirit, in so far 

 as it produces rigidity in bodies and the 

 Power of Resilience. Also, on the Cause of 

 Elasticity. Incidentally, on the Breaking of 

 Glass Drops. 



Nitro-aerial particles fixed in things make them hard, 

 p. 47. Sparks struck from iron seem to catch fire from the 

 nitro-aerial particles contained in them, p. 48. On the 

 hardness of frozen water, p. 49. The cooling quality of nitre 

 seems to come from the nitro-aerial particles, p. 49. Why 



