CARBONIZATION OF TURF. 



183 



very gases may supply the place of one fourth of the turf 

 or combustible employed in the carbonizing fire, an ad- 

 vantage hitherto neglected. 



I would beg leave here to remind the reader of some facts 

 relative to the order in which the gasses are disengaged, 

 during the action of caloric applied to vegetable sub- 

 stances. 



It is known that caloric, in contact with these vegetable Effect of ca- 

 substances, disorganizes them wholly or in part ; that it ,onc- 

 solicits their three remote principles to combine according 

 to their various affinities, and at different temperatures; 

 and that the results are products very different from the 

 original compound. 



Thus, for example, the most volatile substances, or First products, 

 those the principles of which have the strongest attraction water > oU > anct 

 for each other at a low temperature, are first disengaged: 

 the water, oil, and vegetable acid, pass over first, whether 

 they were partly contained in the vegetable substance, or 

 that their principles were induced to combine by the pre- 

 disposing affinity of caloric: but at a high temperature, at 

 a red heat, carbon decomposes water, this ceases to be then carbonic 



formed, and the carbonic acid passes over, with carburetted aci<J > andcar " 



, . ■ , ,.-,,, , buretted hidro- 



nidrogcn surcharged with carbon, and oxidule of carbon ; g en . 



the fixed substances remain in the distilling apparatus; and, 

 if azote be contained in these substances, it is at this period 

 the carbonate of ammonia is disengaged. 



- Though the phenomena taki place in this manner, in small Carbonization, 

 masses, heated equally in all their parts, it is not the case °i t ies dlfterent 

 with several hundred weight of materials, the outside of 

 which will be carbonized, while the centre of the mass has 

 scarcely experienced the effect of the caloric acting in the 

 inverse ratio of the square of the distance. 



Accordingly Ave may expect to find the products differing Proportions of 

 in their proportions at different periods: then the water, gra dually differ. 

 oil, and acid, will predominate at first, and will subse- 

 quently decrease in their proportions, and be more car- 

 bonized. 



We shall then find a black, oily, acrid substance appear, Empyreumatic 

 more or less heavy, which is the empyreumatic oil, and in-° l1 - 

 dicates a carbonization approaching its end in a favourable 

 manner. 



The 



