660 GELA GELATINE and Schroder to edit the collection of Scrip- tores Rerum Suecicarum Medii jExi (2 vols., Stockholm, 1818-'25). His Svea Rikes Edfder (" Annals of Sweden," Upsal, 1825 ; translated into German, 1826) is a collection of disserta- tions on the early history and antiquities of the kingdom. His principal work is the Svenslca Folkets Historia ("History of the Swedish People," 3 vols., Orebro, 1832-'6 ; translated into German by Leffler, Hamburg, 1832-'6; into French by Lundblad, Paris, 1840; and into English by Turner, London, 1845), which extends only to the death of Queen Christina, but has been continued by Carlson. The work of Fryxell is also regarded as a supplement to it. At once a history of ideas, of manners, and of institutions, it is remarkable both for eloquence and learning, for its patriotic tone, synthetic views, and suggestive power. Among his minor publications are a " Sketch of the State of Sweden from Charles XII. to Gustavus III." (Upsal, 1839) and a "Life of Charles XIV. John," or Bernadotte (Upsal, 1844). A com- plete edition of his works has been published (12 vols., Stockholm, 1849-'55). GELA, an ancient city of southern Sicily, on a river of the same name (now Fiume di Terra- nova), founded about 690 B. 0. by a colony of Rhodians from Lindus and Cretans. It soon became flourishing, and was the parent of Agri- gentum (now Girgenti), which afterward sur- passed the mother city. The constitution of Gela was originally oligarchical, but was over- thrown in 505 B. C. by Cleander, who was the first of its tyrants. His brother Hippocrates succeeded him, and extended its influence and power over the greater part of Sicily. His successor Gelon's transfer of the seat of his power and of a part of the inhabitants of Gela to Syracuse (485), his brother Hiero being made governor of the former, caused its decay ; and its desolation was completed about 280 by Phin- tias, tyrant of Agrigentum, who removed its inhabitants to a new town, to which he gave his name. In the time of Augustus it was al- ready in ruins, which are still visible in the vicinity of Terranova. GELATINE, an azotized substance obtained from various parts of the animal body, such as the white fibrous tissue, the skin and serous membranes, and cartilage, by boiling in water. The substance as it exists in the body is proba- bly not precisely the same as that obtained by boiling, although it cannot be said with certain- ty that the proportions of its chemical constit- uents have been changed. No precise formula of equivalents has been established, and it is therefore usual to write the composition of gelatine in percentage parts by weight. Ac- cording to Mulder it consists, in 100 parts, of carbon 50'40, hydrogen 6*64, nitrogen 18'34, and oxygen and sulphur 24'62, of which about 0'7, according to Verdeil, is sulphur ; but the presence of sulphur is disputed, and gelatine, although an azotized, is not a proteine substance. 'Fremy and Scherer make the percentage of nitrogen rather less than that here given. The gelatine of commerce is prepared as fol- lows : The skins of calves 1 heads and other thick pieces which are unfit for the manufac- ture of leather are first freed from hair and thoroughly cleaned of flesh and fat, and well washed. They are then reduced by cutting machinery to small pieces or to a pulp, cold water being allowed to run through the pieces during this operation in order to remove all impurities. The pieces of skin or pulp are differently treated by different manufacturers in order to obtain the solution most readily, some employing the mechanical force of rollers in conjunction with the application of a tem- perature varying from 230 to 250 F. When the solution is obtained it is clarified with some albuminous matter, as the white of eggs or ox blood, and after settling is drawn off upon shallow coolers, as plates of glass or slates. , When partially dry, so that it can be cut into convenient shapes for handling, it is removed upon nets or placed in a vacuum drying ap- paratus to complete the process of desiccation. In the course of the preparation the substance is flavored with essences. Bones and ivory also are made to yield gelatine by subjecting them, when crushed, to water boiling at high temperatures in a digester, or to the action of steam gradually raised to the pressure of 32 pounds to the square inch, and thus kept for 3^ hours. By this means their soluble portions are taken up, and the earthy matters, about 60 per cent, of the whole weight, are left behind, together with a soapy substance produced from the fat and lime of the bones. This residue is used for the manufacture of bone black, or the preparation of phosphorus, and is besides an excellent material for composts. The manufac- ture of gelatine has been largely carried on in France by first removing the earthy salts from bones by digesting them for many days in di- lute hydrochloric acid, and afterward in boiling water. For a long time gelatine was largely employed in the hospitals and pauper estab- lishments of Paris, as a cheap and, as it was believed, very nutritive material for soups. Its value for this purpose was at last ques- tioned, and the commission appointed to in- vestigate its qualities reported unfavorably. It is, however, generally regarded as possessing nutritive properties, though in a less degree than fibrine and albumen ; and even if insuf- ficient itself to support life, its almost uni- versal use in sotae form of food attests its importance as an article of diet. It also finds numerous other uses, as for the clarifying of liquors, in the manufacture of cements, as a chemical test for tannin, and in pharmacy for coating pills and forming pouches or capsules in which disagreeable medicines may be con- cealed and swallowed without disgust. It is also applied in the dressing of silk and other stuffs. It is made by the French into thin transparent sheets called papier glace, which are used for copying drawings ; and they also
