Excerpt from A Study of the Forms in Which Sulphur Occurs in Coal, Vol. 111For some time sulphur in coal has been known to be combined with iron as iron pyrites and marcasite, both of which have the formula fesz. Very small quantities of sulphates also are found, but the amount is so small, especially in freshly mined coal, that it is almost negligible. Free sulphur has been suspected to be present in coal, but its presence is the exception rather than the rule. Iron pyrites is undoubtedly the chief inorganic sulphur compound found in any great quantity in coal.There are many indications that organic sulphur compounds form a large part of the sulphur in coal, but the nature of these compounds or the amount of sulphur so combined has never been determined prior to this investigation. Since the organic sulphur had its source in the protein sulphur of the plant and animal life from which the coal was formed, it is probable that these compounds in the coal are degradation 'products of the original material.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.