The Infrared Spectra of Artificial Coal made from Submerged Wood at Uozu, Toyama Prefecture, Japan

The infrared spectra of artificial coal prepared from Submerged Wood were observed and compared with those of lignin and cellulose. The artificial coalification seems to proceed in three stages, characterized by the corresponding infrared spectra, i. e., a cellulose-like spectrum, a lignin-like spectrum, and a spectrum resembling that of natural coal. The infrared spectrum of artificial coal is generally similar to that of natural coal with a little higher carbon content, suggesting that the degree of coalification is more advanced in artificial coal than in natural coal. The background absorption in the infrared spectra of artificial coal of a low coalification is weak, while that in the infrared spectra of artificial coal of a high coalification is strong.