Page:The New International Encyclopædia 1st ed. v. 17.djvu/71

* BESIDUAL ROCKS. 5 reous rocks, such as limestone or dolomite, furnish in the initial stages of their solution anJ disinte- gration a granular calcareous sand. Joints and other iissure planes in massive rocks greatly facilitate the processes of decomposition and dis- integration. The solutions which are active in these processes find their waj' along the joint planes as trunk lines, and by their more reatly access to the edges and corners of included blocks (if rock soon produce a spheroidal and often con- centric structure. Tluis are brought about spheroidal blocks of the igneous rock type, the centres of which are usually little clianged, but the ])eri])heral zones of which repre- sent altered phases of the rock, the outer- most being the most nearly disintegrated. This process goes on quite rapidly, as is •shown by the fact that monuments and fence posts of basic igneous rocks have within the course of a century so far disintegrated as to be almost useless for the purposes to which they were applied. riant life by sending its roots into the soil protects from disintegration the underlying rocks. In arid regions, however, where little if any plant life can exist, winds are eli'ective in re- mox'ing the superficial layers of waste and con- tinually exposing the iniderlyiug rock. The material removed by the winds on being de- posited produces a?olian rocks. See -Eolian Ac- CUMlL.TION.S. RESIDUARY LEGACY. A legacy of all that remains uf an estate after the debts and specific legacies have been paid. Where a testa- tor desires to give the bulk of his estate to one person, as his wife, and at the same time to make other smaller bequests, it is customary to make the latter by means of express or specific legacies, naming the amount or specific property, and then to devise and bequeath all the 'rest, residue, and remainder' of his estate to the fav- ored person by a residuary clause. It sometimes happens, however, after the delits and minor .specific legacies are paid, that the estate is ex- hausted, and the one whom the testator most in- tended to favor gets nothing. The best method of guarding against this contingency is to put a condition in each of the specitic legacies to the efl'ect that it shall be null and void if the ap- praised value of the estate is not in excess of a certain sum, or to make an express or specific be- quest to the person who is to take precedence over the others, then make the other minor be- quests, and conclude by making the first person the residuary legatee of the rest of the estate. See Legacy; Will. BESINA, rS^-se'na. A, town in the Province of Naples. Italy, situated on the Gulf of Naples, at the foot of Vesuvius, !) miles by rail southeast of Naples (Jlap: Italy. E 11).' It is built on the site of ancient Herculaneum. Exquisite fruits are grown, and the famous Lncrimai Clirisfi wine is made in the vicinity. There are manufactures of silk, glass, and leather. The town is surrounded by country houses, and is a place of recreation for the Neapolitans. The ascent of Mount Vesuvius is begun at Resina. Population (commune), in 1901, 10.766. RESINS (OF. resine. Fr. rcmne, from Lat. retina, resine, from Gk. {i-qrivri. rhrtinc, pinc- Tesin). A class of solid or semisolid oi'ganic substances mostly of vegetable origin. The class > RESINS. includes many minerals which are assumed to be the product of extinct vegetal i<jn. The resins are allied to the volatile oils, in which they are found dissolved when directly obtained from phints. The various resins, all composed of carbon, hy- drogen, and oxygen, diller widely in their cliemi- cal behavior. The following are the general charucters of this class of compounds: At ordinary tcnipcrutures they are solid, translucent, and for the mo.st part colored, although some are colorles.s and transparent. Some are devoid of odor, while others give off an aromatic fragianee from the admixture of volatile oil. In their crude state they never crystallize, but are amorplunis and brittle, breaking with a conchoidal fracture; when puic several of them may, however, lie ob- tained in the crystalline form. " They are reailily melted by the action of heat, and are'inllammalile, burning with a white smoky llame. They are in- solulile in water, but dissolve in alcohol, ether, and various oils. They are insulators or non- conductors of electricity, and become negatively electric liy friction, ilany of them possess acid properties, in which case their alcoholic solutions redden litmus. These resins comhine with (he alkalies, and form frothy .soap-like solutions in alkaline lyes. The resinous soaps thus formeii differ from ordinary soap in not being precipitat- ed by chloride of sodium. The resins are generallj' obtained by making incisions into the wood of trees which ])roihice them; sometimes, however, they exude sponta- neously, and in other cases require to be extracted from the woo<l with hot alcohol or other sul- vents. The crude resins are separated from the volatile oils, with which they form the so-i-alliMl oleo-resiiis, by distillation; and from the gummy and mucilaginous matters with the aid of alco- hol, which dissolves out the pure resins. The resins are e.xtensivel}' used in making lacs and varnishes. Colopliony. copaiba, jalap, podo- phyllum, and the resin of scammony are used nieilicinally. Colophony, or rosin, is an antisep- tic and forms an excellent application for wounds and ulcers. C<i|iaiha acts as a stimulant and dis- infectant, and is often prescribed in gonorrlnea. Podophyllum, jalap, and the resin of scam- mony are purgatives, the latter causing profuse watery evacuation of the bowels. Various fossil rrsiits are known, of which the most important is anilier. Some chemists place asphalt among this class; anil among l!ie fossil resins described by mineralogists may be men- tioned copalin. hartite. xyloretin. etc. Resins also form important constituent.s of the substances known as f/iim reshis (.see (ii'Ms) and are contained in the so-called balsnms. a class of liquid or semi-solid products including benzoin, styrax, and the balsams of Peru and Tohi. Eesins containing Iienzoic or einnamie acid are sometimes spoken of as 'solid balsams.' The common resin or rosin of commerce exudes in a semi-fiuid state from several species of pine, being derived chiefly from the Pinus australis and the Pinus pinaster. The crude turpentine (an oleoresin) obtained from these trees, is distilled, leaving behind the resin, a brittle solid somewhat heavier than water. The resin soap used in the manufacture of common qualities of soap is obtained by boiling rosin for some time with caustic soda and water. Other resins most commonly known and used include copal, dam-