326 Review of Prof. Johnson’s Report on American Coals. 
The weight per cubic foot of the 
Ashes, was - - > - - 56°65 pounds. — 
Clinker - - - : 2) 99-79) oe 
Soot - : - = Z a 5:46 
‘The clinker is brown on the outside ; but on the fractured surfaces 
black, very compact, and heavy ; in sheets of considerable extent, man- 
ifestly very fusible, and tending to adhere to the grate. The highly 
ferruginous character which it presents, isin accordance with the large 
amount of sulphur which was detected in one of the specimens above 
analyzed. 
*« The shaly portions embraced in the vitrified clinker are nearly ob- 
scured by the fusible coating which encloses them. 
“‘ A portion of the specimen 6, above analyzed, was subjected to 
treatment with the oxide of copper: 4°57 grains were thoroughly dried ; 
and the result of their treatment, with all the precautions required by 
the experiment, was of water 2°23, and carbonic acid 14°82 grains. 
“ The earthy matter of the raw coal having been determined, as also 
the moisture, by previous experiments already detailed, it is easy to 
calculate the weight of earthy matter in 4°57 grains of dried coal to be 
0-25274 grain, which leaves of combustible matter 4°31726 grains ; the 
hydrogen, by analysis, is 0°24777, the carbon 4:04182 grains; leaving 
for oxygen and azote only 0:02767, or the relation of these three to 
their sum is— 
Carbon - - £99182 — 93-6200 = 15:60 C. in atoms. 
Hydrogen - - 9.24777 — 5°7391= 5'74H. ch 
Oxygenandazote - $.92787— 0:6409= 0:800. si 
100: 
“Tn the raw coal, this analysis enables me to state that the ingredients 
are— 
Moisture - - - - - - 0914. 
Carbon - - - - - - 87-634 
Hydrogen - - - - - 5372 
Oxygen and azote - - - - 0-600 
Earthy matter = - - - - - 5480 
100: 
“‘ That the relative amounts of carbon and hydrogen were correctly 
determined in the preceding analysis, was rendered highly probable 
by the result of another trial, in which the apparatus became injured 
before the combustion was complete; but the ratio of the two products 
to each other was very nearly the same as in the preceding trial. The 
