ACTION OF SALTS ON VOLATIXS OILS. J53 



saccharums that do not let the oil separate on solution in promoted by 



water, though comnionly the makers are indiiferent about * '"^' 



employing highly rectified oils; not to mention, that the 



most volatile part of the oil must be dissipated by the heat, 



to which it is exposed diiri»»- the baking of the sugar. It 



^ould seem, that in this case the heat must produce a more 



intimate combination with the oil, the nature of which it 



would be interesting to know. 



Exp. 18. As I had at hand a certain number of essen- Experiments 



tial oils, i thought it not amiss to make a series of experi- Ji"ea"orcoM be 



ments, for the purpose of ascertaining the heat or cold they produced on 



would produce when shaken with water. These experiments "'.'^'"g ^'Is 

 1 ^ _ ^ , with water, 



furnished me with a new mode of detecting those adulterated 



by a mixture of spirit of wine. 



1. I mixed volatile oil of peppermint with thrice its Oil of pepper- 



weig-ht of distilled water, and plung;ed a mercurial thermo- """'^* 

 o ' r f3 change. 



meter into the mixture. The temperature was iO" [50° F.], 

 and no change took place. 



2. Common oil of peppermint of the shops, mixed v^ith Common oil 



water in the same proportion, at the same temperature raised of pppp^rm'nt. 



\n \- 0-, Heat, 



the thermometer 1| [27]. 



3. Oil of lemons recently rectified from water on a water oil of lemons, 

 bath, as limpid and as fluid as ether, being shaken with dis- 

 tilled water, produced neither heat nor cold. 



4. Oil of orange flowers recently distilled comported it- Oil of orange 

 self in the ?ame manner; while the orange flower oil of the '^*^''^* 

 shops with the same quantity of water raised the thermome- 

 ter 1° [i-e^. 



These experiments having taught me, that some essential When heat is 

 oils produce neither heat nor cold by their mixture with wa- I'fod need, they 



' "^ areaduUerated 



ter; while others on the contrary produce a sensible heat, with spirit of 

 though operating with very small quantities; I conceived, ^"^^'' 

 that the cause of this heat was ascribable to spirit of wine, 

 employed to adulterate them. Accordingly I mixed one 

 part of spirit of wine with two of an essential oil, kept the 

 mixture some time, and then mixed it with thrice its 

 weight of water, when it caused the thermometer to rise 1* 



ivn 



General 



