316 On Fj/roligncous ^Lher. 



were held in solution chiefly by a very volatile and inflammable 

 fluid. Having separated some of this peculiar fluid from the 

 acid, and deprived it of its colouring matter by repeated recti- 

 fications, I was struck with its strong resemblance to alcohol in 

 jnany of its characters. 



I found it perfectly miscible with water : — that it dissolved 

 camphor and all the gum resins quite as readily and as abun- 

 dantly as alcohol does ; that it burned with a flame like that of 

 alcohol ; and that its specific gravity varied from 830 to 900, 

 according to the care taken in its rectification. 



As I had convinced myself that this spirit might be obtamed 

 in considerable quantity, and would be useful for various pro- 

 cesses in the arts, I was naturally led to think how far its simi- 

 larity to spirits of wine might subject it to the excise laws ; and 

 I made a scries of experiments to ascertain if it could truly be 

 called alcohol. 



Many of these experiments were rather interesting; but I will 

 at this tune only mention one, which, in my opinion, proves its 

 non-identity with alcohol. 



Taking a quantity of this spirit which I had rectified as per- 

 fectly as possible, I added to it the same proportion of sulphu- 

 ric acid that is usually employed to produce sulphuric aether. 

 Instead of obtaining sdier, I found a spirit still miscible with 

 water, and burning with a blue flame ; its smell being some-, 

 what altered and its specific gravity a little reduced. 



The residuum in the retort was a black pitchy substance, 

 which became perfectly hard and brittle on cooling. 



From what I have stated it is obvious that this fluid is neither 

 alcohol, nor an essential oil, but probably a new variety of 

 sether. 



M. Diibereiner appears to suppose that birch-wood espe- 

 cially yields this spirit ; but I have found it equally in pyrolig- 

 neous acid fi-om various other woods. 



It appears to me that there is no difficulty in accounting for 

 the formation of this spirit; which, fi-om its greater resemblance 

 to aether than to any other substance, I have called fyroligneous 

 (ether. It is well known that no acetic acid exists in wood ; 

 yet on exposing it to destructive distillation acetic acid is 

 formed : that is to say, the carbon, hydrogen, and oxygen are 

 liberated from their original combination by the action of the 

 heat ; and meeting together under favourable circumstances, 

 they recombine and form acetic acid. The pyroligneous aether 

 is also a ternary compound on the same three simple sub- 

 stances, but in different proportions; and the quantity of it pro- 

 duced will be found to vary according to the circumstances 

 under which the distillation of the wood is conducted. I have 



constantly 



