216 



Having thus furnished you with the particulars of that chemical 

 process by which an oil is formed from substances which would not 

 d priori have been expected to yield it, we will now endeavour to 

 ascertain how far that process resembles the presumed process of 

 bituminization. In the first place, then, the substances acted upon, 

 by the supposed bituminous fermentation, as well as by the vinous 

 fermentation, are the same dead vegetable matter. Secondly, as 

 in the vinous fermentation, so in the bituminous fermentation, a 

 peculiar acid and a peculiar combustible substance is formed; 

 those of each process resembling each other in their component 

 principles ; this resemblance being particularly close between the 

 combustible substances resulting from each process : each possess- 

 ing a high degree of levity and inflammability ; each being formed 

 of hydrogen, combined with a large proportion of carbon and of 

 oxygen ; and each manifesting, that the principles of which they 

 are composed are not in a very intimate state of union. 



I am anxious, before I conclude this letter, to place before you 

 some of the reasons which have induced me to suppose the ligneous 

 substance to be that part of vegetables which is most particularly 

 acted on, by the species of fermentation which I have assumed ; 

 as well as to point out to you a circumstance, which, in my opinion, 

 yields strong, I had almost said internal, evidence of the necessity 

 of such a species of fermentation. 



gas, an oily fluid is formed; and that by the employment of the same acid, in a more 

 powerful manner, an actual tallow like grease is produced. Another consideration, 

 which seems to corroborate this opinion, of the different steps of this progress to an ole- 

 aginous state, depending on certain added proportions of carbon, combined with oxy- 

 gen, is, that oil itself, the ultimatum of this process, holds so considerable a portion of 

 carbon, that this principle constitutes a large proportion of every one of its products^ 

 which are carburetted hydrogen, carbonic acid, and charcoal; whilst the quantity of 

 oxygen which it contains is also so great that it manifests a degree of acidity, in a very 

 short time, merely by the addition of what it attracts from the air. 



