l66 HISTORY OF PITCOAL. 



ject, in CQiisort with those romances concerning the origiu 



of metullic veins, to which our age has given birth. 



Coal as nnich J ],ave said, that analysis discovers in these bitumens cha- 



resenibles an '' 



animal as a ve- racters, that do not show a greater affinity to vegetables 



getable pro- than to animals. The following are the facts : and 1 leave 



it to the learned to decide which way the balance inclines. 



Its smell not J, Thp ^mell that coals exhale when heated is avomatic, 



■wood bu° succin^ted, and decidedly resinous: it irritates neither the 



fricndjy to the eyes nor the lungs, like that of wood or vegetables when burn- 



"^^s- ej. and this resinousr smell has ev^n been considered as 



friendly to the diseases of the chest. 

 Softens and 2. All coals soften, Icjse their shape, run, mould them- 



by^heat?^ ^^ selves to the shape of the retort, and fill it with a spongy or 

 puffy coal, like that common to mucous substances, resins, 

 indigo, gluten, and animal matters; ]3ut npt like that of any 

 known wood or- plant. 

 Yields more oil ^. Distillation obtains from it a lighter, more aromatic, 

 ammonia, ^^^ niore abundi^nt oil, than the nonresinous woods used fo^r 

 but no vinegar, fuel; and 4 great deal of water and ammonia, but none of 

 that vinegar, which abounds in the distillation of our vege- 

 tables ; that encipyreumatic acid, which reriders thpir smoke 

 so troublesome and suffocating; vinegar whic'h is formed, 

 whenever oxigen is an integrant part of ap organic oxide, 

 and the absence of which in the products of coal would au- 

 thprise us in a certain degree to doubt, that oxigen is one of 

 its products*. 

 Coak does not 4, The combustipn of coak does npt at all resemble that 

 ?eTwood •''^'''' ^^ ^^^ vegetable charcoals.. It is slow and difficult like t\m% 

 of mineral coals, because it likewise contains condensed ni^ 

 trogen ; accordingly it requires a condensed atmosphere to 

 burn it. *' 



affords prussic 5, Coak passed through potash always affords a prussic 



' lixivium, which vegetable charcoals in general do not. 

 cannot be set 6. Animal charcoal cannot be set on tire by nitric aci(|, 

 on fire by mtric ^y^^ after it is disazotizf d by potash : neither can coak, everi 

 passed through this alkali. 



Pyroliirneous * ^ f^"" some time doubted the fact, that the pyroligneous acid wac 



acid formsace- really vinegary but J am now convinced of it, as the sail I formed with 

 ttite of copper, pxlde of copper and the acid of elm displayed is characters after three 



purifications. It gave larsje rhombs^^ difxeriug in no respect from acetate 



of copper. 



A ri|ixture 



