Page:Encyclopædia Britannica, Ninth Edition, v. 6.djvu/590

556 spirits of wine. The art of painting in crayons or pastils is supposed to have originated in Germany in the 17th century. By Johann Alexander Thiele (1685-1752) it was carried to great perfection, and in France it was early practised with much success. Amongst celebrated crayon- painters may be mentioned Camera liosalba (1G75-1757), W. Hoare (1707-1792), F. Cotes (1726-1770), J. Russell (1744-1806), and the late Mr Bright.  {{ti|1em|{{larger|CREAM OF TARTAR}}, acid potassium tartrate,or &quot;bitar- trate of potash/ 1 HKC 4 O H 4, is obtained from argol or crude tartar, the crust or deposit formed by wines in bottles and casks in which they are undergoing fermentation. Red are usually richer in argol than white wines. A ton of grapes yields, according to the nature of the fruit, quantities vary- ing between 1 and 2 K&amp;gt; of argol, of which, in good samples, an average of about 83 per cent, is cream of tartar. French red wines examined by M. Faur6 contained from 06664 to 19728 per cent, by weight of this salt, and white wines from 09172 to 15208 per cent. ; M. Jacob found from 7 to 1 201 grammes per litre in the wines of Tonnerre. The manufacture of cream of tartar is conducted as follows. Ground granulated argol is wetted and then dis- s jived in water at a temperature of 100 C. ; after two or three days, during which insoluble impurities subside, tha clear liquid is drawn off into earthen vessels. The crystal.} it deposits are re-dissolved in boiling water holding finely comminuted pipe-clay and animal-charcoal in suspension. The solution after standing till a thin film of crystals appears on its surface is run into conical coolers, the sides of which become in eight or nine days coated with fmo clear crystals, colouring matters having been precipitated by the cl vy and charcoal. The crystals are then bleached and dried by exposure to sunlight and air. In Venice the impurities of the crude tartar are separated by repeated crystallizations, and finally by adding white of egg and wood-ashes to the boiling solution, and removing the scum formed. The uame &quot; cream of tartar &quot; was originally given to the crust of minute pure white crystals formed on the surface of cooling solutions. Cream of tartar is a colour less, transparent salt, crystallizing in four-sided prisms belonging to the trimetric system, and having a specific gravity of about 1 - 96. It is precipitated when a potassium salt is added to a solution of free tartaric acid. It is soluble in alkalies, alkaline carbonates, and mineral acids, but insoluble in acetic acid and alcohol. Its insolubility in the last mentioned is the cause of its separation from wines as they mature. One part by weight of the salt is soluble at C. in about 416 (Chancel), and at 100 C. in about fifteen parts of water. The solution has an acid reaction, and dissolves many metallic oxides, furnishing double tartrates. When heated, cream of tartar is decom posed, with the formation of potassium carbonate (the sal- fixum tartari of the older chemists) and carbon, inflammable gases possessing an odour of burnt bread being at the same time evolved. Potassium carbonate is produced also when the salt is kept moist or in solution for some years. Cream of tartar potasses tartras acida is used in medicine as a refrigerant, diuretic, and mild purgative; in dyeing as a mordant for wool; in the manufacture of tartaric acid and potassium carbonate ; and with powdered chalk and alum for cleaning silver. Eochelle salt, KNaC 4 O H 4, is made by neutralizing cream of tartar with sodium carbonate ; tartar emetic, K(SbO)C 4 O G H 4, by boiling it with three-fourths of its weight of antimony trioxid-e, filtering the hot solution, and crystallizing. Black flux, the result of the incineration of tartar is much employed in assaying, and may be prepared by deflagrating two or three parts of the salt with one of nitre ; for white flux equal weights of the two salts are required. Tartars, even those intended for the manu facture of tartaric acid, should be free from any considerable quantity of calcium tartrate, as the moisture of the airsooa converts that salt into calcium carbonate. The substances most used to adulterate cream of tartar are calcium chloride and sulphate, and the chloride and acid sulphate of potassium.}}  CREASOTE,, or (/cpea?, flesh, and O-W&LV, to save), is a product of the distillation of wood-tar, more especially that made from beech-wood ; tar from the wood of conifers contains it in but small quantity. Tho distillation of the tar is carried on till only a thick pitchy substance is left. From the lowermost layer of the distillate is obtained by the action of sodium carbonate a yellowish oil, the heavier part of which is isolated by rectification in a glass retort, and mixed with potash solution to dissolve out its creasote. The creasote is separated from the filtered potash solution by sulphuric acid, is distilled with alkalino water, and again treated with potash and acid, till its purification is effected ; it is then distilled at 200 C. (392 7 Fahr.), and dried by means of calcium chloride. Creasoto is r, highly refractive, colourless, oily liquid, first obtained by Reichenbach, in 1832, from beech-wood tar. It con sists mainly of a mixture of the compounds phenol, C H 5 .OH, cresol, C,H 4 .CH 3 .OH, phlorol, C 6 H 3 (CH 3 ).,.OH, guaiacol, C H 4. CH 3. OH, and creosol, C G H 3. CH 3. OCHg. OH. The so-called coal-tar creasote is more or less impure carbolic acid, containing paracresol and other bodies. Creasote hao r, strong odour and hot taste, is a non-con ductor of electricity, and burns with a smoky flame. It3 specific gravity is 1 037 at 20 C. ; its boiling point is 203 C. (397 Fahr.); and it is still liquid at -27 C. ( - 16 6 Fahr.) Rhenish creasote can be distilled for tho most part between 199 and 208 C., giving a liquid of specific gravity 1 077 at 14 C. Creasote dissolves sul phur, phosphorus, resins, and many acids and colouring matters ; and is soluble in alcohol, ether, and carbon disulphide, and in 80 parts by volume of water. It is distinguished from carbolic acid or phenol by the following qualities : it turns the plane of a ray of polarized light to the right, forms with collodion a transparent fluid, and is nearly insoluble in glycerine ; whereas carbolic acid has no effect on polarized light, gives with about two-thirds of its volume of collodion a gelatinous mass, and is soluble in all proportions in glycerine; further, alcohol and ferric chloride produce with creasote a green solution, turned brown by water, with carbolic acid a brown, and on the addition of water, a blue solution. Creasote, like carbolic acid, is a powerful antiseptic, and readily coagulates albuminous matter; wood-smoke and pyroligneous acid or wood-vinegar i owe to its presence their efficacy in preserving animal and ! vegetable substances from putrefaction. Creasote is given in medicine combined with acetic acid, syrup, spirit of juniper, and water. In small quantities it acts as a sedative of the stomach, but in over-doses it is a violent poison, causing severe pain in the abdomen, nausea, headache, giddiness, and stupor. It is administered in cases of vomiting, diarrhoea, cholera, intestinal bleeding, and chronic gleet, and to assuage hunger and thirst in diabetes ; in the form of a gargle it is of service in excessive salivation, and its vapour, mixed with that of water, is sometimes recommended for inhalation. Externally it is applied as a stimulant and styptic, and for the treatment of decayed teeth ; and an ointment containing it is used as a remedy for /ing-worm. Creasote is also employed for preserving timber from dry-rot, and for the curing of fish and hams. The principal supplies of creasote are brought from Archangel, Stockholm, and America.  CRÉBILLON, (1707-1777), a French novelist and wit of the 18th century, was the only son of Crebillon, the tragic poet. His life was spent at Paris, except about five years, during which, on account 