Page:The American Cyclopædia (1879) Volume XVI.djvu/289

 VARNISH whiteness of the paper, does not reflect light disagreeably as resinous varnishes do, and is not liable to scale off. Another valuable var- nish, called "milk of wax," is prepared by melting a certain quantity of white wax, add- ing to it while in fusion an equal quantity of alcohol, of specific gravity 0'83, stirring the mixture, and pouring it out upon a porphyry- slab, on which it is ground with a muller until it becomes smooth and homogeneous, when water is mixed in by degrees to the amount of four times the weight of the wax, and the emulsion finally strained through canvas. This may be spread with a smooth brush on the surface of a painting, allowed to dry, then fused by passing a hot iron over it, and when cold rubbed with a linen cloth to bring out the lustre. To some such process as this the an- cient paintings on the walls of Herculaneum and Pompeii owe their freshness at the present day. Prof. Bottger proposes the following black varnish for zinc: Dissolve 2 parts of nitrate of copper and 3 parts of chloride of copper in 64 parts of water, and add 8 parts of nitric acid. Puscher's method is as follows : He dissolves equal parts of chlorate of potash and sulphate of copper in 36 times as much warm water, and leaves the solution to cool. The zinc castings are immersed for a few seconds in the solution, or the sheets may be washed with a sponge, which turns them quite black with oxide of copper. They are then washed and dried, and the coating is rubbed with a cloth, which imparts a glittering indigo appearance. Milk of wax varnish may then be applied, which gives the surface a deep black color and gloss. The following com- prise some of the best recipes for varnishes : VARRO 269 INGREDIENTS. L 9. 3. 4. 8. c. 7. a 9. 10. n. 12. 13. Shell lac Ibs 2 2 li 1 Mastic, " . 1 2 4 4 4 fi 1 Copal, " 8 7 8 8 1

1 1 Y 4 9 Y. 1 1 Oil of turpentine, " Linseed oil, " 8 2 3 ?* 0* 2* g Turpentine varnish,. 1 Venice turpentine, oz. IS 18 Y 4 Black sealing wax, Ibs .. 8 Asnhalt. Ibs... No. 1 is copal varnish for fine paintings; 2, cabinet varnish; 3, best body copal varnish, for bodies of coaches, &c., which require polish- ing ; 4, carriage varnish for parts not requiring to be polished; 5, best white hard spirit var- nish ; 6, white spirit varnish for violins ; 7, brown hard spirit varnish ; 8, turpentine var- nish ; 9, crystal varnish ; 10, amber varnish ; 11, paper varnish; 12, sealing wax varnish; 13 and 14, black varnishes. Besides all these compound varnishes, the liquid resins which exude from many species of trees, especially in China, Japan, Burmah, and India, are used as varnishes, either crude or with slight prepa- ration. (See JAPANNING.) The Chinese var- nish is said to be produced by the augia Si- nensis, and is black when simply dried, but is colored by various pigments. The Japan var- nish of Kampfer and Thunberg is rJius vernix, and that of the Malayan islands stagmaria verniciflua. The juice of holigarna longifolia is used in Malabar for varnishing shields ; the Burmese varnish tree is melanorrhosa, and a fine liquid varnish is yielded by vateria Indica and F. lancecefolia. A resinous juice is also employed by the Feejeeans as a varnish or glaze for their pottery. YAROLI, Costanzo, an Italian anatomist, born in Bologna about 1543, died in Rome in 1575. He studied medicine at Bologna, and acquired considerable distinction as a teacher of anat- omy there, but removed to Rome on being appointed physician to Pope Gregory XIII. He was especially distinguished for his dissec- tions of the brain, which he was the first to ex- amine from the base upward, instead of from above downward, as had previously been the custom. He first fully described the arched bundle of nervous matter passing from side to side across the central parts of the base of the brain, and now known, from its resemblance in form to a bridge, as the pom Varolii. His principal works are De Nerms Opticis, nonnul- lisque aliis, prater communem opinionem in Humano Capite olservatis (Padua, 1573), and De Eesolutione Corporis Humani, published after his death (Frankfort, 1591). VARRO, Marcus Terentins, a Roman scholar, horn in the Sabine town of Reate in 116 B. C., died in 28. He received a liberal education, held a high office in the navy in the wars against the pirates and against Mithridates, and at the commencement of the civil war was serving in Spain as legate of Pompey. When Cffisar marched into that country after the re- duction of Italy, Varro was obliged to surren- der his forces ; but still adhering to the aris- tocratic party, he joined Pompey in Greece and remained faithful to him until the victory of Pharsalia (48) had made Csesar master of the Roman world. Varro's villa at Casinum was taken and plundered by Antony, but Csesar treated him kindly, and employed him to su- perintend the collection and arrangement of the works in the library at Rome designed for the public use. From this time Varro lived in retirement. During the second triumvirate he was put by Antony on the list of the pro- scribed, but by the aid of friends his life was saved, though his libraries were destroyed. Augustus appointed him superintendent of the library founded by Asinius Pollio. According to a list traceable to himself, Varro wrote 74 works in 500 or 600 books, including several in metrical form, and prose treatises on nearly