FLUORESCENCE 463 



people in Europe who excelled in the art of making artificial flowers ; but of late 

 years the French have been most ingenious in this branch of industry. 



Ribbons folded in different forms and of different colours were originally employed 

 for imitating flowers, by being attached to wire stems. This imitation soon gave way 

 to that by feathers, which are more delicate in texture, and more capable of assuming 

 a variety of flower-like figures. But a great difficulty was encountered in dyeing them 

 with due vivacity. The savages of South America manufacture perfect feather flowers, 

 derived from the brilliant plumage of their birds, which closely resemble the products 

 of vegetation. The blossoms and leaves are admirable, while the colours never fade. 



The Italians employ frequently the cocoons of the silkworm for this purpose ; these 

 take a brilliant dye, preserve their colour, and possess a transparent velvety appear- 

 ance, suitable for petals. Of late years, the French have adopted the finest cambric 

 for making petals, and the taffeta of Florence for the leaves. M. de Bernardiere 

 employs whalebone in very thin leaves for artificial flowers ; and, by bleaching and 

 dyeing them of various hues, he has succeeded in making his imitations of nature 

 very remarkable. 



Gutta-percha dissolved in benzole, and freed from all impurities, will, when spread 

 out on a sheet of glass, dry into a beautifully white and delicate film, of great strength, 

 and capable of receiving any colour. This has been employed in Paris in the manu- 

 facture of flowers. Vegetable parchment (paper prepared by the action of sulphuric 

 acid) has been employed for the same purpose in this country. See VEGETABLE 

 PARCHMENT, 



The colouring matters used in flower-dyeing are the following : 



For red ; carmine dissolved in a solution of carbonate of potash. 



For blue ; indigo dissolved in sulphuric acid, diluted and neutralised in part by 

 Spanish whitening. 



For bright yellow ; a solution of turmeric in spirit of wine. Cream of tartar 

 brightens all these colours. 



For violet ; archil, and a blue bath. For lilac ; archil. 



The aniline colours are now largely used. 



Some petals are made of velvet, and are coloured merely by the application of the 

 finger dipped in the dye. 



Artificial flowers imported were of the values given in each year : 



Value Value Value 



1868 . . 341,176*. 1869 . . 365,407*. 1870 . . 266,502/. 



In 1872 we imported from 



Value 

 Germany --. . . . . . 4,657?. 



Belgium . . 18,966 



France 387,768 



Other countries ... 149 



Total .... 411,510?. 



FXiTTATES. A term formerly applied to the compounds now called fluorides, on 

 the supposition that they contained fluoric acid. When, however, the true constitu- 

 tion of this acid, as a hydrogen-compound, was determined, it became evident that 

 the substances called fluates must belong to the class of so-called haloid salts, and 

 consist therefore of the element fluorine united directly with a metal or radical ; 

 whence they are properly termed fluorides. Thus, fluor-spar, formerly known as fluate 

 of lime, is, according to the new nomenclature, a fluoride of calcium ; containing 

 fluorine, 487; calcium, 51'3. 



It may be remarked that fluorine has a strong tendency to form double salts, many 

 of which occur native. Thus, the minerals called cryolite and chiolite are double 

 fluorides of sodium and aluminium. 



FLUE CINDER. The cinder from the reheating furnace. See IKON MANU- 

 FACTURE. 



FLUELLXTE. A rare mineral, containing fluorine and aluminium, found at 

 Stennagwyne in Cornwall. 



FLUXES. See ANCHOR. 



FLUOR. See FLUOR-SPAR. 



FLUORESCENCE, the name given to a peculiar phenomenon rendered evident 

 by many crystals of fluor-spar. If we look through a crystal of fluor-spar it will 

 appear yellow or green as the case may be ; now, if we look at it, the light falling 

 upon the surface upon which we look, it will appear beautifully blue or purple. 

 Prof. Stokes, to whom we are indebted for a very exact examination of the whole of 



