330 M. Karsten's Observations and Experiments 



coal, occurs in that of mineral charcoal ; when this substance 

 presents itself isolated among the other parts of the coal, it dif- 

 fers from it only in having a much greater proportion of char- 

 coal. But its composition is regulated by the relations which 

 exist among the constituent parts of the mass of coal, in the 

 midst of which it occurs interposed. This proves that the same 

 circumstances were in action during the formation of both sub- 

 stances, but that the mineral-charcoal was more quickly formed, 

 the cause of which can only be sought for in the original nature 

 of the vegetable fibres. 



M. Karsten presents, in a tabic, the results of some of the 

 comparative trials to which he submitted mineral charcoal and 

 coal, both coming from the same spot. The following are the 

 results of distillation in the dry way, for 100 parts of each of 

 the two substances. 



Places from which thk Spkci- 

 - mens analysed came. 



1. Mine oC Glucksburg, near 



Ibbenljuhren, - - 



2. Another mine in the 



same place, - - - 



3. Mine of the circle of 



Westphalia, - - - 



4. Mine of the neighbour- "j 



hood of Waldenburg > 

 (Lower Silesia), - J 



5. Mine of Konigsgrube ) 



(Upper Silesia), - j" 



16. Mine of Pottschapel, ) 

 near Dresden, . - J 



Mineral Charcoal. 



Residue in 

 Charcoal, 

 in 100 parts 



90 



95.3 



97.4 



91.9 



89.85 

 79.33 



Ashes com- 

 ing from 

 the residue 

 in Charcoal 

 for 100 

 parts. 



2.8 

 2.2 

 1.06 



3.95 



7.55 

 1.3 



Remains in 

 pure Char- 

 coal for 100 

 parts. Con- 

 tents in 

 Charcoal. 



Coal of the same 

 localities. 



Residue in Charcoal 

 after abstraction 

 made of the Ashes, 

 for 100 parts. Con- 

 tents in Carbon. 



{ 

 { 



5.74 I 

 87.95 



93.2 

 93.1 

 95 



82.30 

 78.03 



87.9 Pulveru- 

 lent Coke. 



81. Intumesced 

 Coke. 



91.4 Pulveru- 

 lent Coke. 



59.8 Intumesced 

 Coke. 



63.2 Congluti 

 nated Coke. 



41 Intumesced 

 Coke. 



It is known, that, in the dry distillation, the coals, with in- 

 tumesced coke, on account of their greater contents in hydro- 

 gen, always afford less charcoal in proportion than such coals, 

 whether with conglutinated coke or with pulverulent coke, as 

 have really the same contents in carbon. In recalling this fact 

 to mind, we see, by the preceding table, that the contents in 

 carbon of mineral charcoal are entirely regulated by the nature 

 of the coal, in the midst of which it presents itsel(. For ex- 

 ample;, in the same manner as Nos. 1. and 2. of the table bear 



