_Process of ascertaining_ the ABSORBENT POWER OF SOILS, _and other substances._ Thoroughly dry the article by the suitable application of a heat not exceeding 212° Fahr., continued for several hours, and transfer it, while still warm, into a clean dry phial furnished with a perfectly tight ground-glass stopper. When cold, quickly and cautiously introduce it, along with a delicate hygrometer, into a large wide-mouthed glass bottle, the atmosphere of which has been previously rendered as damp as possible, by suspending a piece of moistened rag or filtering paper in it. It must now be kept closed for some hours, when the hygrometer will indicate the degree of dryness of the enclosed air, and, consequently, the absorbent power of the substance examined. _Obs._ Experiments of this nature are only relatively correct, and must be performed under exactly similar circumstances, to furnish reliable comparative results. The whole process, in each case, must be as similar as careful manipulation can possibly make them. With this reserve, they will be found invaluable to the agriculturist. =Absorption.= In _chemistry_ the passage of gases and vapours into liquid and solid substances. Thus, water absorbs the oxygen of the air, lime absorbs water, charcoal absorbs ammoniacal and other gases. =Absorption.= In _medicine_ and _toxicology_, see MEDICINES and POISONS. =Absorption.= In _perfumery_, see ENFLEURAGE. =Absorption.= In _physics_, see HEAT, LIGHT, REFRIGERATION, &c. =Absorption.= In _physiology_ (animal and vegetable), the function of sucking, or taking up, of appropriate substances, by the ‘absorbent vessels.’ It is one of the chief vital functions, the primary object of which is to convey to the circulatory organs the proper supply of the materials necessary for the support and growth of the body; and subsequently, to remove and convey to these organs its effete and useless portions, in order to their ultimate elimination from the system. =Absorption.= In _surgery_, the natural process by which tumours and their contents, morbid growths, and, sometimes, even healthy glands, &c., are gradually taken up and disappear, by the action of the ‘absorbents.’ =Absorption= (of Surfaces, Moulds, &c). See ABSORBENT SURFACES. =ABSTERG′ENTS.= _Syn._ ABSTERGEN′TIA, L. In _medicine_ and _pharmacy_, substances which cleanse or clear away foulness from the surface of the body or sores; as soap, lotions, &c. See DETERGENT, which has a nearly similar meaning, and is in more general use.