A sample of this material has recently been analyzed by Prof. Atwater, at the Connecticut Agricultural Station at Middletown. The analysis shows that it contains no more organic matter than Prof. Voelcker found in fresh earth prepared for use in the closet,--say about two hundred pounds,--nearly all of which organic matter it undoubtedly contained when first made ready for use. In my case, there was an addition, at a moderate calculation of at least, 800 pounds of solid dry matter during the six years' use by an average of four adult persons. Prof. Voelcker's analysis showed that the unused earth contained about twelve pounds of nitrogen. Prof. Atwater's analysis shows that my two tons contained only about eleven pounds of nitrogen. By calculation, the 800 pounds of solid dry matters added in the use of my material contained 230 pounds of nitrogen. Doubtless the constitution of Prof. Voelcker's sample was somewhat different from the original constitution of my own; but practically, except perhaps for the addition of a trifling amount of residual carbon remaining after the decomposition, they were about the same; and, after being used ten times over, the whole of the 800 pounds of organic matter added, including 230 pounds of nitrogen, seem to have entirely disappeared. It becomes interesting and important to know what has become of this added matter. That it was absorbed into the particles of the earth, is a matter of course; and the result proves that after such absorption it was subjected to such a chemical action of the concentrated oxygen always existing in porous dry material as led to its entire destruction. Porous substances condense gases--air, oxygen, etc.--in proportion to the extent of their interior surface. The well-known disinfecting action of charcoal--the surface of the interior particles of which equal from fifty to one hundred square feet to each cubic inch of material, and all of which surface is active in condensing oxygen--is due not simply to an absorption of foul-smelling odors, but to an actual destruction of them by slow combustion, so that the same mass of charcoal, if kept dry and porous, will continue almost indefinitely its undiminished disinfecting action.