168 



HtSTORY OF PITCOAL. 



Coal treated 

 witli nitric 

 acid. 



reduced to 

 coak. 



This not the 



The same as 

 produced in 

 distillation. 



Hence the 



never succeed with any vegetable or animal production we 

 know. 



Let powdered coal, such as that of Villanucva, wliich af- 

 fords 68 per cent of coak, be heated in nitric acid of 18° or 

 20®; and thus in a few moments it will be- deprived of the 

 property it had before of forming' oil, oily gas, and ammo- 

 nia. The coal thus prepared, washed, and dried, and then 

 exposed to a moderate heat, affords products of a new order, 

 but with indications of those just mentioned, and is reduced 

 to '66 or *67 of coak. 



All pitcoals afford this extraordinary result, which is ob- 



case even with tained from no organic production known, not even from in- 

 incugo. . . . 



digo, though it contains '7- or '73 of charcoal, or much more 



than many kinds of pitcoal. 



The carbonaceous principle, freed from the other ele- 

 ments of the compound by this method, has all the proper^ 

 ties of what would be obtained by the simple distiHation of 

 pitcoal ; for, if it be treated with potash, it gives a prussic 

 lixivium like coak itself. I proceed to the conse((uences. 



If in these bitumens the carbonaceous part be thus feebly 



blackness and enchained by the other elements, and consequently approach 

 brittleness of . . ' . . . , • i i "^ , 



coal. in its properties charcoal uncombmed, we need not be sur- 



prised either at the blackness or fragility of pitcoal. 

 The charcoal The Carbonaceous principle of organized bodies, freed 



m coal retains fj^Q^ ^\^q fetters of combination by any means, and conse- 

 gome hidrogen , ^ ■, - ' 



and nitrogen, quently brought nearly to its natural density, may not sepa- 

 rate totally from the hidrogen and nitrogen, in consequence 

 of the reciprocal affinity of these three combustibles ; as is 

 shown by the habitual state of the coal in our fires, which 

 always contains more or less of them : but the same cannot 

 but no ox-gen. be said of the oxigen. The condensation of the charcoal, 

 carried to the degree that makes it appear black, is a state 

 decidedly opposing the capacity of this principle to adhere 

 to it as easily as the oihers. This admitted, if the charcoal 

 in these bitumens be near its habitual density, we must not 

 be surprised, that, remaining still united with the nitrogen 

 and hidrogen, it cannot be equally so with the oxigen. On 

 this principle neither is it strange toUnd, that pitcoal does 

 liot contain oxigen in a state to concur, during its distilla- 



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