STOPPER. 598 STORAGE BATTERY. length of soft manila secured at one end to the structure of the ship ; the other end is passed around the rope to be stoppered with a jamming hitch. It is used to keep the rope from slipping while it is being belayed or secured. A stopper for a chain cable is usually of wire rope and four to six feet long. At one end it is spliced into the eye of a hook, and at the other has an STOPPER FOE CHAIN CABLE. eye formed around a short bar of iron. The hook is placed in a ringbolt in the deck, and the body of the stopper lashed to the chain by two 'tails' of soft manila rope. When ships are at anchor the chain is held by such stoppers. STORAGE (from store, OF. estorer, estaurer, from Lat. instaurare, to renew, make, provide, from in, in + *staurare, to set up; connected with Gk. aravpdc, stauros, stake, Skt. sthavira, firm, AS. stCor, rudder, and ultimately with Eng. stand). Since most plants absorb or produce food in excess of their inmiediate needs, they provide for temporary or long-continued storage. These foods are transformed for permanent stor- age and mobilized for subsequent translocation by specific activities of the cell, self-regulated through irritability (q.v.). The chief re- gions of storage are spores, seeds, fleshy fruits, roots, tubers, bulbs, leaves, and stems. As a rule the regions of the higher plants specially adapted for storage are thick, fleshy, and abundantly supplied with thin-walled parenchyma cells. ( See Histology.) Storage occurs only in living cells. Occasionally the cell walls in storage regions are thick and woody, and in some cases, e.g. in the endosperm of seeds, the walls themselves are made up mainly of the stored material, re- serve cellulose. The chief forms in which reserve food is stored are as follows : . ( 1 ) Cabbohtdr-tes. Reserve carbohydrates are either soluble, such as sugars (saccharose, glucose, fructose, mannose, and galactose) and inulin, or insoluble, as starch and cellulose (qq.v.). Starch is organized into granules by the leucoplasts (q.v.). Reserve cellulose is de- posited upon the cell walls as a complex carbo- hydrate, whose composition is unknown, though it seems to have somewhat the same relations to ordinary cellulose as the most complex of the dextrins, amylodextrin, holds to starch. It is found especially in the endosperm, or in various parts of the embryo, in bud scales, etc. (2) Fats. Fats occur in the form of minute droplets (oil) in the protoplasm, not infrequent- ly accumulated by special organs of the cell, the leucoplasts. They are found in the endosperm or embryos of seeds (probably in the seeds of nine-tenths of all seed plants), in spores, tubers, and the wood of trees. (3) Proteids. Proteids are found either as amorphous grains, the so-called aleurone, or as crystals, which are not infrequently associated with or imbedded in aleurone grains. These are sometimes formed by leucoplasts. but at other times appear to be deposited in the sap cavity (vacuoles) of cells, where the proteid appears to accumulate in increasing concentration until it solidifies in the form of the vacuole, or in one or several crystals. (See Aleurone.) Crystals of proteid are also found in cliromato- phores, nuclei, and even in the cytoplasm itself. They are often distinguished as crystalloids, be- cause they have the capacity of swelling (see liiBiBiTiox ) , a rare quality among inorganic crystals. (4) Amides. Amides are nitrogenous com- pounds intermediate in complexity between pro- teids and carbohydrates and readilj- crystalliza- ble. Most nitrogenous materials are ordinarily translocated as amides. They are rare in seeds, but especially abundant in the sappy reservoirs, such as bulbs, tubers, rhizomes, etc., where they constitute 40 to 70 per cent, of the total food. The different kinds of storage materials are more or less definitely associated. Thus the re- serve food may consist of proteids and sugar (e.g. the pea and onion) ; proteids and starch (e.g. the potato, the embiyo of beans, pea, etc.) ; proteids and oil (e.g. the endosperm of the castor bean and the cotyledons of the soja bean) ; or proteids, oil, and reserve cellulose (e.g. the endo- sperm of the date and coffee) ; or proteids, with oils in the cotyledons and mucilage in the endo- sperm walls (e.g. clover). The reason for the special association of reserve foods is not known. Insoluble reserve foods are only transportable after digestion (q.v.). STORAGE BATTERY. An accumulation of energy which is able to produce directly an elec- tric current. The term is a misnomer, as elec- tricity itself cannot be stored. A so-called stor- age battery or accumulator when acted upon by a current undergoes certain chemical changes. The chemicals which are thus separated recom- bine again when the circuit of the battery is closed, and in uniting give off a current of elec- tricity about equal to that by which they were decomposed. Lead is the metal most commonly used in accumulators, the positive plate having a coating of lead peroxide, PbO,, and the negative plate a surface of spongy lead. The idea of the storage cell may be traced back to 1801, at which time Gautherot showed that platinum wires used in the electrolysis of saline solutions developed secondary currents. Later, in 1803, Ritter constructed a secondaiy pile of copper disks separated by cloths moistened with a solution of sal ammoniac. By charging this a few moments with a powerful galvanic battery the pile gave a strong shock. Volta, Beequerel, and others discovered that platinum and other metals — gold, silver — gave secondary electric currents when subjected to electrolytic action in certain solutions. In 1842 Grove pro- duced his celebrated gas battery, which gave a current by means of the difference in polarity of oxygen and hydrogen, the constituents of water. In Faraday's Researches he mentions the high conductivity of peroxide of lead at the negative pole. Gaston Plants was the first to apply this principle, and constructed in 1860 his cell with coiled plates, the first practical storage battery, which was afterwards developed and modified by Faure. Metzger, Brush, and others. Storage batteries may be divided into two gen- eral classes: Those in which the active material (peroxide of lead) is formed on the surface of the plates by chemical or electro-chemical action, and those in which some easily reducible salt of
