MLA CITATION: Polo, Marco, Henry Yule, and Henri Cordier. The Travels of Marco Polo: The Complete Yule-Cordier Edition: Including the Unabridged Third Edition (1903) of Henry Yule's Annotated Translation, as Revised by Henri Cordier, Together with Cordier's Later Volume of Notes and Addenda (1920). New York: Dover Publications, 1993. Print.
BOOK SECOND. PART I. CHAPTER XXX. CONCERNING THE BLACK STONES THAT ARE DUG IN CATHAY, AND ARE BURNT FOR FUEL
It is a fact that all over the country of Cathay there is a kind of black stone existing in beds in the mountains, which they dig out and burn like firewood. If you supply the fire with them at night, and see that they are well kindled, you will find them still alight in the morning; and they make such fine fuel that no other is used throughout the country. It is true that they have plenty of wood also, but they do not burn it, because those stones burn better and cost less. [Moreover with the vast number of people and the number of baths they maintain—for every one has such a bath at least three times a week, and in winter if possible every day, whilst every nobleman and man of wealth has a private bath for his own use—the wood would not suffice for the purpose.] (SOURCE)
MLA CITATION: Wikipedia. Wikimedia Foundation. Web. 08 Mar. 2016.