666 PHILOSOPHICAL TRANSACTIONS. [aNNO 1 Spir 



scarcely any thing which lies long in the fire but is apt to retain some igneous 

 particles ; which appears to be so in all fixed salts, in quick-lime, and more 

 particularly in iron. If you take a bar of iron, though of a hundred years old, 

 and file off about a pound of it, and then mix and imbibe these filings with a 

 due proportion of water, enough to make the whole just moist ; the fire, which 

 all this while lay concealed in the iron, being more disposed to enter into the 

 fluid, does by these means warm the whole mass. The iron gained this heating 

 quality by fusion in those fierce fires which first separated the metal from the 

 ore. For it is not in the nature of the ore before fusion to emit any heat, as I 

 have found by mixing water with it. There are a great many other instances 

 which make it very plain that fire will add both to the bulk and weight of bodies; 

 but these affect solid bodies more manifestly. The effect itself produced by our 

 fluid does necessarily prove the inherent fiery particles to have caused the 

 accension. 



Oils may be distinguished into vegetable, animal, and mineral ; we subdivide 

 again the vegetable into those made by expression, and those made by distilla- 

 tion ; and of those made by distillation we distinguish those that are made out 

 of the seeds from those that are made out of the trunks, or cortex, or roots, 

 or any other part of the vegetable. We further observe a difference between 

 those seeds that have only a fragrant smell and a pungent taste alone, from 

 those that have both odorous emanations and a brisk taste together, and those 

 that are insipid and have no smart taste. In the first place we must set aside 

 those oils made by expression ; for having tried oils of linseeds, of nuts, of 

 olives, of almonds, &c. we found these would not make explosion or ebullition, 

 or so much as any fermentation with our fiery meteor. Nor could I, without 

 much stirring, bring them to incorporate ; and when they did incorporate the 

 heat was but just sensible. To examine briefly the mineral oils; there are 

 some, as oil of vitriol, oil of sulphur per campanam, that have not any pro- 

 perty of oils, but are rather acids, and corroding menstruums. There are 

 others that have the true property of essential oils, as oleum petrolei, and Bar- 

 badoes tar highly rectified, which do not produce any remarkable heat, much 

 less make an ebullition or explosion: nor does that active oil of amber do any 

 thing more. The stillatitious oil of bees-wax had much the same effect when 

 it was incorporated with our compound fiery spirit ; and this inclines me to be- 

 lieve that the wax itself may be a compound more belonging to a mineral than 

 vegetable nature. Now of those essential oils, which produce great ebullition, 

 explosion, and flame, with the compound spirit, we have two sorts, vegetable 

 and animal. The true vegetable essential oils all make violent ebullition and 

 explosion, and several actually take fire and flame. If it be inquired what share 



