[Fig. 939.] is a side view and section of Wagenmann’s apparatus for cooling worts; [fig. 940.], a view from above. The preceding contrivances seem to be far preferable.
a, a, is the tub for receiving the apparatus, whose central upright shaft b, rests upon a step c, in the bottom, and revolves at top in a bush at d, made fast to a bar e, fixed flat across the mouth of the tub. The shaft may be driven by the two bevel wheels f, f, at right angles to each other, and the horizontal rod turned by hand; or the whole may be impelled by any power. g, is an iron basin for receiving the cold water from the spout h, supplied by a well; it flows out of the basin through two tubes i i, down into the lower part of the cooler k k. The cooler consists of two flat vessels, both of which are formed of a flat interior plate, and an arched exterior one, so that their transverse section is plano-convex. The water which flows along the tubes i i, spreads itself upon the bottom of the cooler, and then rises through the scabbard-shaped tubes l l, &c., into the upper annular vessel m m; whence it is urged by hydrostatic pressure, in a now heated state, through the slanting tubes n n, which terminate in the common pipe o, of the annular basin p p, and is thence discharged by the pipe q. The basin p p, is supported by the two bearers r, made fast to the cross-beam e. There is in the lowest part of the hollow ring at bottom, a screw plug, which may be opened when it is desired to discharge the whole contents, and to wash it with a stream of water.
REGULUS, is a term introduced, by the alchemists, now nearly obsolete. It means literally a little king, and refers to the metallic state as one of royalty, compared with the native earthy condition. Antimony is the only metal now known by the name of regulus.
RESINS (Résines, Fr.; Harze, Germ.); are proximate 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 in summer through the bark into the wood of the tree.
Resins possess the following general properties:—They are soluble in alcohol, insoluble in water, and melt by the application of heat, but do not volatilize without partial decomposition. They have rarely a crystalline structure, but, like gums, they seldom affect any peculiar form. They are almost all translucid, not often colourless, but generally brown, occasionally red or green. Any remarkable taste or smell, which they sometimes possess, may be ascribed to some foreign matter, commonly an essential oil. Their specific gravity varies from 0·92 to 1·2. Their consistence is also very variable. The greater part are hard, with a vitreous fracture, and so brittle as to be readily pulverized 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 heated, they melt more or less easily into a thick viscid liquid, and concrete, on cooling, into a smooth shining mass, of a vitreous fracture, which occasionally flies off into pieces, like Prince Rupert’s drops; especially after being quickly cooled, and scratched with a sharp point. They take fire by contact of an ignited body, and burn with a bright flame, and the diffusion of much sooty smoke. When distilled by themselves in close vessels, they afford carbonic acid and carburetted gases, empyreumatic oil of a less disagreeable smell than that emitted by other such oils, a little acidulous water, and a very little shining charcoal. See [Rosin Gas].
Resins are insoluble in water, but dissolve in considerable quantities in alcohol, both hot and cold. This solution reddens tincture of litmus, but not syrup of violets; it is decomposed by water, and a milkiness ensues, out of which the particles of the resin gradually agglomerate. In this state it contains water, so as to be soft, and easily kneaded between the fingers; but it becomes hard and brittle again when freed by fusion from the water. The resins dissolve 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. Chlorine water bleaches several coloured resins, if they be diffused in a milky state through water. The carburet of sulphur dissolves them.
Resins are little acted upon by acids, except by the nitric, which converts them into artificial tan. They combine readily with the alkalis and alkaline earths, and form what were formerly reckoned soaps: but the resins are not truly saponified; they rather represent the acid constitution themselves, and, as such, saturate the salifiable bases.
Every resin is a natural mixture of several other resins, as is the case also with oils; one principle being soluble in cold alcohol, another in hot, a third in ether, a fourth in oil of turpentine, a fifth in naphtha, &c. The soft resins, which retain a certain portion of volatile oil, constitute what are called balsams. Certain other balsams contain benzoic acid. The solid resins are, [amber], [animé], benzoin, [colophony] (common rosin), [copal], dammara, [dragon’s blood], elemi, [guaiac], [lac], resin of jalap, ladanum, [mastic], [sandarach], [storax], [takamahac].
RESIN, KAURI or COWDEE, is a new and very peculiar substance, recently imported in considerable quantities from New Zealand, which promises to be useful in the arts. It oozes from the trunk of a noble tree called Dammara australis, or Pinus kauri, which rises sometimes to the height of 90 feet without a branch, with a diameter of 12 feet, and furnishes a log of heart timber of 11 feet. The resin, which is called Cowdee gum by the importers, is brought to us in pieces varying in size from that of a nutmeg to a block of 2 or 3 cwts. The colour varies from milk-white to amber, or even deep brown; some pieces are transparent and colourless. In hardness it is intermediate between copal and resin. The white milky pieces are somewhat fragrant, like elemi. Specific gravity, 1·04 to 1·06. It is very inflammable, burns all away with a clear bright flame, but does not drop. When cautiously fused, it concretes into a transparent hard tough mass, like shellac. It affords a fine varnish with alcohol, being harder and less coloured than mastic, while it is as soluble, and may be had probably at one-tenth of the price. A solution in alcohol, mixed with one-fourth of its bulk of a solution in oil of turpentine, forms an excellent varnish, which dries quickly, is quite colourless, clear, and hard. It is insoluble in pyro-acetic (pyroxilic?) spirit. Combined with shellac and turpentine, it forms a good sealing-wax.