Gysser gives the following comparisons of a good peat with various German woods and charcoals, equal weights being employed, and split beech wood, air-dry, assumed as the standard.
"Peat and its Uses as Fertilizer and Fuel"
Samuel William Johnson
He now looks thoughtfully about for a rag to scour it withal; there is a rag of sooty environment and inferentially sooty antecedents hanging beside a box of charcoals next to the chimney-place; he horrifies some among us by promptly catching it up; gives the pan a vigorous rubbing-out with this carboniferous relic; and certain appetites for omelet fade swiftly away.
"A Midsummer Drive Through The Pyrenees"
Edwin Asa Dix
And I lately noted to you out of Bellonius, that the charcoals of Oxy-cedar are not of the former of these two Colours, but of the latter.
"Experiments and Considerations Touching Colours (1664)"
Robert Boyle