VARIETY VARNISH. 



785 



VARIETY, in natural history, a subdivision of; 

 species, as a species is a subdivision of a genus, j 

 What one naturalist considers a variet}, another | 

 sometimes considers a distinct species. Most of ; 

 the various kinds of dogs are varieties which can be ' 

 reduced to a few species. A variety cannot be i 

 preserved without much care : left to nature, it re- ! 

 turns, in a succession of generations, to the species. 



VARIORUM, CUM NOTIS. Certain editions of 

 ancient and modern Latin and Greek authors, pub- ; 

 lished mostly in Holland, in the seventeenth and \ 

 eighteenth centuries, and containing the notes of 

 many commentators, are termed editiones cum nntis 

 variorum. These editions do not stand in very 

 high estimation with scholars, but are, nevertheless, 

 sought for by collectors. The number is given dif- 

 ferently by bibliographers, according as they enu- 

 merate more or fewer new editions of this kind pub- 

 lished out of Holland. 



VARIOUS READINGS (lectlones variantcs, 

 lectiones varice} are differences in the text of a work, 

 which sometimes originate from the ignorance or 

 negligence of the early transcribers of manuscripts, 

 sometimes from the changes which an author makes 

 himself in the later editions of his works. To re- 

 store the true text of ancient works is the business 

 of verbal criticism, and is often very important; 

 e. g. in classic authors, the Bible, &c. Some edi- 

 tions contain all the various readings in notes. 



VARNA : a town of European Turkey, in Bul- 

 garia; 1 12 miles north-east of Adrianople. and 144 

 north of Constantinople ; Ion. 27 59' E. ; lat. 43 

 T N. ; population, 16,000. It has an old castle, 

 twelve mosques, two Greek churches, the most 

 commodious port in Bulgaria, and a large trade with 

 Constantinople. It is situated on a gulf or bay of 

 the Black sea, to which it gives name, at the mouth 

 of the river Varna. In 1444, Ladislaus, king of 

 Hungary, was defeated and slain by Amurath I., 

 sultan of the Turks, near this town. In 1783, 

 Varna resisted the attacks of the Russians ; but, 

 October 11, 1828, it was taken possession of by the 

 Russian forces. See Russia. 



VARNISH. Lac varnishes, or lacquers, consist 

 of different resins in a state of solution, of which 

 the most common are mastich, sandarach, lac, ben- 

 zoin, copal, amber, and asphaltum. The menstrua 

 are either expressed or essential oils or alcohol. 

 For a varnish of the first kind, the common paint- 

 ers' varnish is to be united, by gently boiling it, 

 with some more mastich or colophony, and then 

 diluted with a little more oil of turpentine. The 

 latter addition promotes both the glossy appearance 

 and drying of the varnish. Of this sort also is the 

 amber varnish. To make this varnish, half a pound 

 of amber is kept over a gentle fire, in a covered 

 iron pot, in the lid of which there is a small bole, 

 till it is observed to become soft, and to be melted 

 together into one mass. As soon as this is per- 

 ceived, the vessel is taken from the fire, and suf- 

 fered to cool a little, when a pound of good paint- 

 ers' varnish is added to it, and the whole suffered 

 to boil up again over the fire, keeping it continually 

 stirring. After this, it is again removed from the 

 fire, and, when it is become somewhat cool, a pound 

 of oil of turpentine is to be gradually mixed with 

 it. Should the varnish, when it is cool, happen to 

 be yet too thick, it may be attenuated with more 

 oil of turpentine. This varnish has always a dark- 

 brown colour, because the amber is previously half- 

 burned in the operation ; but, if it be required of a 

 blight colour, amber powder mhst be dissolved in 



transparent painters' varnish, in Papin's machine, 

 by a gentle fire. As an instance of the second sort 

 of lac varnishes with ethereal oils alone, may be 

 adduced the varnish made with oil of turpentine. 

 For making this, mastich alone is dissolved in oil 

 of turpentine by a very gentle, digesting heat, in 

 close glass vessels. This is the varnish used for 

 the modern transparencies, employed as window- 

 blinds, fire-screens, and for other purposes. These 

 are commonly prints, coloured on both sides, and 

 afterwards coated with this varnish on those parts 

 that are intended to be transparent. Sometimes 

 fine thin calico, or Irish linen, is used for this pur- 

 pose ; but it requires to be primed with a solution 

 of isinglass before the colour is laid on. Copal may 

 be dissolved in genuine Chio turpentine, by adding 

 it in powder to the turpentine, previously melted, 

 and stirring till the whole is fused. Oil of turpen- 

 tine may then be added to dilute it sufficiently. A 

 varnish of the consistence of thin turpentine is ob- 

 tained by the digestion of one part of elastic gum, 

 or caoutchouc, cut into small pieces, in thirty-two 

 parts of naphtha. Previously to its being used, 

 however, it must be passed through a linen cloth, 

 in order that the undissolved parts may be left be- 

 hind. The third sort of varnishes consists of the 

 spirit varnishes. The most solid resins by them- 

 selves produce brittle varnishes ; therefore some- 

 thing of a softer substance must always be mixed 

 with them, whereby this brittleness is dimi- 

 nished. For this purpose, elemi, turpentine, or 

 balsam of copaiva, are employed in proper propor- 

 tions. For the solution of these bodies, the strongest 

 alcohol ought to be used. In conformity to these 

 rules, a fine-coloured varnish may be obtained by 

 dissolving eight ounces of gum sandarach and two 

 ounces of Venice turpentine in thirty-two ounces 

 of alcohol by a gentle heat. Five ounces of shell- 

 lac, and one of turpentine, dissolved in thirty-two 

 ounces of alcohol, by a very gentle heat, give a 

 harder varnish, but of a reddish cast. To these 

 the solution of copal is undoubtedly preferable in 

 many respects. This is effected by triturating an 

 ounce of powdered gum copal, which has been well 

 dried by a gentle heat, with a drachm of camphor, 

 and, while these are mixing together, adding, by 

 degrees, four ounces of the strongest alcohol, with- 

 out any digestion. Between this and the gold 

 varnish there is only this difference, that some sub- 

 stances that communicate a yellow tinge are to be 

 added to the latter. Take two ounces of shell-lac, 

 of annotto, and turmeric, of each one ounce, and 

 thirty grains of fine dragon's blood, and make an 

 extract with twenty ounces of alcohol, in a gentle 

 heat. Oil varnishes are commonly mixed immedi- 

 ately with the colours ; but lac or lacquer varnishes 

 are laid on by themselves upon a burnished coloured 

 ground. When they are intended to be laid upon 

 naked wood, a ground should b first given them of 

 strong size, either alone or with some earthy colour, 

 mixed up with it by levigation. The gold lacquer 

 is simply rubbed over brass, tin or silver, to give 

 them a gold colour. Before a resin is dissolved in 

 a fixed oil, it is necessary to render the oil drying. 

 For this purpose, the oil is boiled with metallic 

 oxides, in which operation, the mucilage of the oil 

 combines with the metal, while the oil itself unites 

 with the oxygen of the oxide. To accelerate the 

 drying of this varnish, it is necessary to add oil of 

 turpentine. The essential varnishes consist of a 

 solution of resin in oil of turpentine. The varnish 

 being applied, the essential oil flies off, and leavrs 



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