700 RESINS 



a saving of heat is effected. Dr. Percy suggests that accwm.ula.tors would be a better 

 term. 



REGUXiUS. A name introduced by the alchemists, and applied by them in the 

 first instance to antimony ; it signifies the little king ; and from the facility with which 

 antimony alloyed with gold, these empirical philosophers had great hopes that this 

 metal antimony would lead them to the discovery of the philosopher's stone. 



'In the smelting of certain sulphuretted ores the product obtained in the first 

 instance is a sulphide of the metal ; and this product has received different names in 

 different metallurgical works. In English copper works the word metal is commonly 

 used to denote compounds of this kind, that of regulus being applied in a specific 

 sense to certain kinds of metal. I shall, however, adopt the word regulus in the 

 present work as a generic appellation for all similar products. The Germans 

 designate regulus by the synonymous terms Stein and Lech, and the French by the 

 term matte. It is frequently the case that in one smelting operation, slag, regulus, 

 and metal are obtained, which are superposed in the order mentioned, which is that 

 of their respective specific gravities.' (Percy, Metallurgy.') 



In our metal-imports ' ore ' and ' regulus ' are commonly named. The regulus 

 must be regarded as an impure metal. 



REHEATING, in metallurgy. In iron manufacture, puddled bars are brought 

 to a welding heat in furnaces, called Reheating or Welding furnaces, they are then 

 passed through rolls to bring them into the condition of merchant iron. 



REISNER. A process of inlaying wood, like Parquetry. 



REIiBUTC. The South-American name for the roots of the Calceolaria arach- 

 noidea, used for dyeing crimson by the natives. 



REOTTET. The gastric juice of the stomach of the sucking calf, which, being 

 extracted by infusion immediately after the death of the animal, serves to curdle milk. 

 As the juice passes rapidly into putrefaction, the stomach must be salted after the 

 outer skin has been scraped off, and all the fat and useless membranes carefully 

 removed. It is only the inner coat which is to be preserved after it is freed from any 

 curd or other extraneous matter in the stomach. The serum left in it should be 

 pressed out with a cloth, and is then to be replaced in the stomach with a large 

 quantity of the best salt. The skins, or veils, as they are called, are next put into a 

 pan and covered with a saturated solution of salt, and soaked for some hours ; but 

 there should be no more brine than covers the veils. They are afterwards hung up 

 to dry, a piece of wood being put crosswise into each to stretch them out. They 

 should be perfectly dried, and look like parchment. In this state they may be kept in 

 a dry place for any length of time, and are always ready for use. 



Pieces of veil are cut off and soaked for some hours in whey or water, and the 

 whole is added to the warm milk for curdling it, its strength having been first 

 tested on a small quantity. By the rapidity with which it curdles, and the form of 

 the flakes, a judgment is formed of its strength, and the quantity required for the 

 whole milk. 



REPOUSSE. Metal-work in relief. The metal plate is placed upon a wax block, 

 and by means of a punch and hammer, the ornamental design is hammered up. 



RESIN 1 , KAURI or COWJDEE, is a peculiar resinous substance, imported from 

 New Zealand. It oozes from the trunk of a noble tree called Dammara Australia. 

 See UAMM A it. 



RESINS (Besines, Fr. ; Harze, Ger.) are principles found in most vegetables, 

 and in almost every part of them; but the only resins which merit a particular 

 description are those which occur naturally in such quantities as to be easily collected 

 or extracted. They are obtained chiefly in two ways, either by spontaneous exudation 

 from the plants, or by extraction by heat and alcohol. In the first case, the discharge 

 of resin in the liquid state is sometimes promoted by artificial incisions made through 

 the bark into the wood of the tree. 



Resins possess the following general properties : They are soluble in alcohol, in 

 ether and the volatile oils, and with the aid of heat, combine with the unctuous oils. 

 They may be combined by fusion with sulphur, and with a little^ phosphorus. They 

 are insoluble in water, and melt by the application of heat, but do not volatilise 

 without partial decomposition. They are almost all translucid, not often colourless, 

 but generally brown, occasionally red or green. Any remarkable taste or smell, 

 which they sometimes poseess, may be ascribed to some foreign matter, commonly an 

 essential oil. Their specific gravity varies from 0'92 to T2. Their consistence is 

 also very variable. The greater part are hard, with a vitreous fracture, and so brittle 

 as to be readily pulverised in the cold. Some of them are soft, a circumstance 

 probably dependent upon the presence of a heterogeneous substance. The hard resins 

 do not conduct electricity, and they become negatively electrical by friction. When 



