"I think the sky is blue because it's a shift from black through purple</p> to blue, and it has to do with where the light is. You know, the farther we get into darkness, and there's a shifting of color of light into the blueness, and I think as you go farther and farther away from the reflected light we have from the sun or the light that's bouncing off this earth, uh, the darker it gets ... I think if you look at the
out, it's the shifting of color. We mentioned before about the stars
singing, and that's one of the effects of the shifting of colors."
-- Pat Robertson, The 700 Club
At this, a flood of tears Lavinia shed; A crimson blush her beauteous face o'erspread, Varying her cheeks by turns with white and red. The driving colors, never at a stay, Run here and there, and flush, and fade away. Delightful change! Thus Indian iv'ry shows, Which with the bord'ring paint of purple glows; Or lilies damask'd by the neighb'ring rose.
This was more than M. Gillenormand could bear to hear. At the word republic, he rose, or, to speak more correctly, he sprang to his feet. Every word that Marius had just uttered produced on the visage of the old Royalist the effect of the puffs of air from a forge upon a blazing brand. From a dull hue he had turned red, from red, purple, and from purple, flame-colored.
"Yes, excellency; I hastened to the river, sat down on the bank, and with my knife forced open the lock of the box. In a fine linen cloth was wrapped a new-born child. Its purple visage, and its violet-colored hands showed that it had perished from suffocation, but as it was not yet cold, I hesitated to throw it into the water that ran at my feet. After a moment I fancied that I felt a slight pulsation of the heart, and as I had been assistant at the hospital at Bastia, I did what a doctor would have done--I inflated the lungs by blowing air into them, and at the expiration of a quarter of an hour, it began to breathe, and cried feebly. In my turn I uttered a cry, but a cry of joy. 'God has not cursed me then,' I cried, 'since he permits me to save the life of a human creature, in exchange for the life I have taken away.'"
There also, laden with its fruit he form'd A vineyard all of gold; purple he made The clusters, and the vines supported stood By poles of silver set in even rows. The trench he color'd sable, and around Fenced it with tin. One only path it show'd By which the gatherers when they stripp'd the vines Pass'd and repass'd. There, youths and maidens blithe In frails of wicker bore the luscious fruit, While, in the midst, a boy on his shrill harp Harmonious play'd, still as he struck the chord Carolling to it with a slender voice. They smote the ground together, and with song And sprightly reed came dancing on behind.
Ferrous salts give a greenish precipitate with an alkali, whilst ferric give a characteristic red one. Ferrous salts also give a bluish white precipitate with ferrocyanide, which on exposure turns to a dark blue; ferric salts are characterized by the intense purple >coloration with a thiocyanate. (See also CHEMISTRY, § _Analytical_). For the quantitative estimation see ASSAYING. Entry: IRON
BREWING CHEMISTRY.--The principles of brewing technology belong for the most part to physiological chemistry, whilst those of the cognate industry, malting, are governed exclusively by that branch of knowledge. Alike in following the growth of barley in field, its harvesting, maturing and conversion into malt, as well as the operations of mashing malt, fermenting wort, and conditioning beer, physiological chemistry is needed. On the other hand, the consideration of the saline matter in waters, the composition of the extract of worts and beers, and the analysis of brewing materials and products generally, belong to the domain of pure chemistry. Since the extractive matters contained in wort and beer consist for the most part of the transformation products of starch, it is only natural that these should have received special attention at the hands of scientific men associated with the brewing industry. It was formerly believed that by the action of diastase on starch the latter is first converted into a gummy substance termed dextrin, which is then subsequently transformed into a sugar--glucose. F.A. Musculus, however, in 1860, showed that sugar and dextrin are simultaneously produced, and between the years 1872 and 1876 Cornelius O'Sullivan definitely proved that the sugar produced was maltose. When starch-paste, the jelly formed by treating starch with boiling water, is mixed with iodine solution, a deep blue coloration results. The first product of starch degradation by either acids or diastase, namely soluble starch, also exhibits the same coloration when treated with iodine. As degradation proceeds, and the products become more and more soluble and diffusible, the blue reaction with iodine gives place first to a purple, then to a reddish colour, and finally the coloration ceases altogether. In the same way, the optical rotating power decreases, and the cupric reducing power (towards Fehling's solution) increases, as the process of hydrolysis proceeds. C. O'Sullivan was the first to point out definitely the influence of the temperature of the mash on the character of the products. The work of Horace T. Brown (with J. Heron) extended that of O'Sullivan, and (with G.H. Morris) established the presence of an intermediate product between the higher dextrins and maltose. This product was termed maltodextrin, and Brown and Morris were led to believe that a large number of these substances existed in malt wort. They proposed for these substances the generic name "amyloins." Although according to their view they were compounds of maltose and dextrin, they had the properties of mixtures of these two substances. On the assumption of the existence of these compounds, Brown and his colleagues formulated what is known as the maltodextrin or amyloin hypothesis of starch degradation. C.J. Lintner, in 1891, claimed to have separated a sugar, isomeric with maltose, which is termed isomaltose, from the products of starch hydrolysis. A.R. Ling and J.L. Baker, as well as Brown and Morris, in 1895, proved that this isomaltose was not a homogeneous substance, and evidence tending to the same conclusion was subsequently brought forward by continental workers. Ling and Baker, in 1897, isolated the following compounds from the products of starch hydrolysis--maltodextrin-[alpha], C_{36}H_{62}O_{31}, and maltodextrin-[beta], C_{24}H_{42}O_{21} (previously named by Prior, achroodextrin III.). They also separated a substance, C_{12}H_{22}O_{11}, isomeric with maltose, which had, however, the characteristics of a dextrin. This is probably identical with the so-called dextrinose isolated by V. Syniewski in 1902, which yields a phenylosazone melting at 82-83° C. It has been proved by H. Ost that the so-called isomaltose of Lintner is a mixture of maltose and another substance, maltodextrin, isomeric with Ling and Baker's maltodextrin-[beta]. Entry: BREWING
_Physical Features._--Three characteristic physiographic regions are distinctly marked: first the great Colorado Plateau, some 45,000 sq. m. in area, embracing all the region N. and E. of a line drawn from the Grand Wash Cliffs in the N.W. corner of the state to its E. border near Clifton; next a broad zone of compacted mountain ranges with a southern limit of similar trend; and lastly a region of desert plains, occupying somewhat more than the S.W. quarter of the state. The plateau region has an average elevation of 6000-8000 ft. eastward, but it is much broken down in the west. The plateau is not a plain. It is dominated by high mountains, gashed by superb canyons of rivers, scarred with dry gullies and washes, the beds of intermittent streams, varied with great shallow basins, sunken deserts, dreary levels, bold buttes, picturesque mesas, forests and rare verdant bits of valley. In the N.W. there is a giddy drop into the tremendous cut of the Grand Canyon (q.v.) of the Colorado river. The surface in general is rolling, with a gentle slope northward, and drains through the Little Colorado (or Colorado Chiquito), Rio Puerco and other streams into the Grand Canyon. Along the Colorado is the Painted Desert, remarkable for the bright colours--red, brown, blue, purple, yellow and white--of its sandstones, shales and clays. Within the desert is a petrified forest, the most remarkable in the United States. The trees are of mesozoic time, though mostly washed down to the foot of the mesas in which they were once embedded, and lying now amid deposits of a later age. Blocks and logs of agate, chalcedony, jasper, opal and other silicate deposits lie in hundreds over an area of 60 sq. m. The forest is now protected as a national reserve against vandalism and commercialism. Everywhere are evidences of water and wind erosion, of desiccation and differential weathering. This is the history of the mesas, which are the most characteristic scenic feature of the highlands. The marks of volcanic action, particularly lava-flows, are also abundant and widely scattered. Entry: ARIZONA
2. _Forastero._--Pods relatively thick-walled and hard. The seeds vary in colour from pale to deep purple. Various varieties are recognized, such as cundeamor, amelonado, liso, calabacillo, differing in shape, colour and character of beans, &c., and of each of these again there may be a colorado and amarillo sub-variety. Of special interest is calabacillo, a variety with a smooth, small pod, and deep purple beans. It is considered by some to be sufficiently distinct to form a third type equivalent to criollo or forastero. Others again would raise amelonado to the rank of a distinct type. Of the above calabacillo is the hardiest and yields the least valuable beans; criollo is the most delicate and yields beans of the highest value, whilst forastero is intermediate in both respects. In general pale coloured beans are less bitter and more valuable than purple beans. Both, however, may occur in the same pod. Entry: 2
The following are well-known synthetic indicators: hacmoid, obtained from resorcin and sodium nitrite, resembles litmus. Phenolphthalein, obtained by condensing phenol with phthalic anhydride, is colourless both in acid and in neutral solution, but intensely red in the presence of alkali; the colour change is very sharp with strong bases, but tardy with weak ones, and consequently its use should be restricted to acidimetry when a strong base can be chosen, or to alkalimetry when a strong base is present. [alpha]-Naphtholphthalein has also been used (_Biochem. Zeit._, 1910, p. 381). Methyl orange, which is the sodium salt of the acid helianthin, obtained by diazotizing sulphanilic acid and coupling with dimethylaniline, is yellow in neutral and alkaline solutions, but red in acid; the change is only sharp with strong acids. Para-nitrophenol, obtained in the direct nitration of phenol, yields a colourless solution in the presence of acids, and an intense yellow with alkalis. Of more recent introduction are: alizarin red, I.W.S. (alizarin mono-sulphonic acid), claimed by G. E. Knowles (_Abst. J.C.S._, 1907, ii. 389) to be better than methyl orange in alkalimetry; 3-amino-2-methylquinoline, used by O. Stark (ibid. 1907, i. 974) in ammonia estimations; para-nitrobenzeneazo-a-naphthol, shown by J. T. Hewitt (_Analyst_, 1908, 33, p. 85) to change from purple to yellow when alkalis are titrated with weak acids; para-dimethylaminoazobenzene-ortho-carboxylic acid, proposed by E. Rupp and R. Loose (_Ber._, 1908, 41, p. 3905) as very serviceable in the estimation of weak bases, such as the alkaloids or centinormal ammonia; the "resorubin" of M. Barberio (_Gazzetta_, 1907, ii. 577), obtained by acting with nitrous acid on resorcin, which forms a violet, blue or yellow coloration according as the solution is neutral, alkaline or acid. Mention may be made of E. Linder's (_J. Soc. Chem. Ind._, 1908, 27, p. 485) suggestion to employ metanil yellow, obtained by coupling diazotized meta-aminobenzenesulphonic acid with diphenylamine for distinguishing mineral from organic acids, a violet coloration being produced in the presence of the former. Entry: INDICATOR
_Perchromic Acid._--By the addition of hydrogen peroxide to a solution of chromic acid, a fine blue coloration due to a perchromic acid is produced which is readily absorbed by shaking out with ether. The following formulae have been assigned to the compound:--H2O2·CrO3 (H. Moissan, _Comptes rendus_, 1883, 97, p. 96); H2O2·2HCrO4 (M. Berthelot, _Comptes rendus_, 1889, 108, p. 25); Cr2O7·xH2O (L.C.A. Barreswil, _Ann. chim. et phys._, 1847 [3], 20, p. 364), and CrO6·3{H2O} (T. Fairley, _Chem. News_, 1876, 33, p. 237). The more recent investigations of H.G. Byers and E.E. Reed (_Amer. Chem. Jour._, 1904, 32, p. 503) show that if metallic potassium be added to an ethereal solution of the blue compound at -20° C., hydrogen is liberated and a purple black precipitate of the perchromate, of composition KCrO4 or K2Cl2O8, is produced; this compound is very unstable, and readily decomposes into oxygen and potassium bichromate. Similar sodium, ammonium, lithium, magnesium, calcium, barium and zinc salts have been obtained. It is shown that the blue solution most probably contains the acid of composition, H2Cr2O8, whilst in the presence of an excess of hydrogen peroxide more highly oxidized products probably exist. Entry: BICHROMATES
Potassium gives a blue-violet flame which may be masked by the colorations due to sodium, calcium and other elements. By viewing the flame through an indigo prism it appears sky-blue, violet and ultimately crimson, as the thickness of the prism is increased. Other elements do not interfere with this method. Sodium gives an intense and persistent yellow flame; lithium gives a carmine coloration, and may be identified in the presence of sodium by viewing through a cobalt glass or indigo prism; from potassium it may be distinguished by its redder colour; barium gives a yellowish-green flame, which appears bluish-green when viewed through green glass; strontium gives a crimson flame which appears purple or rose when viewed through blue glass; calcium gives an orange-red colour which appears finch-green through green glass; indium gives a characteristic bluish-violet flame; copper gives an intense emerald-green coloration. Entry: 4
Down to the middle of the 19th century natural dyestuffs alone, with but few exceptions, were at the command of the dyer. But already in the year 1834 the German chemist Runge noticed that one of the products obtained by distilling coal-tar, namely, aniline, gave a bright blue coloration under the influence of bleaching powder. No useful colouring matter, however, was obtained from this product, and it was reserved for the English chemist Sir W.H. Perkin to prepare the first aniline dye, namely, the purple colouring matter Mauve (1856). The discovery of other brilliant aniline dyestuffs followed in rapid succession, and the dyer was in the course of a few years furnished with Magenta, Aniline Blue, Hofmann's Violet, Iodine Green, Bismarck Brown, Aniline Black, &c. Investigation has shown that the products of the distillation of coal-tar are very numerous, and some of them are found to be specially suitable for the preparation of colouring matters. Such, for example, are benzene, naphthalene and anthracene, from each of which distinct series of colouring matters are derived. In 1869 the German chemists Graebe and Liebermann succeeded in preparing Alizarin, the colouring matter of the madder-root, from the coal-tar product anthracene, a discovery which is of the greatest historical interest, since it is the first instance of the artificial production of a vegetable dyestuff. Another notable discovery is that of artificial Indigo by Baeyer in 1878. Since 1856, indeed, an ever-increasing number of chemists has been busily engaged in pursuing scientific investigations with the view of preparing new colouring matters from coal-tar products, and of these a few typical colours, with the dates of their discovery, may be mentioned: Cachou de Laval (1873); Eosin (1874); Alizarin Blue (1877); Xylidine Scarlet (1878); Biebrich Scarlet (1879); Congo Red (1884); Primuline Red (1887); Rhodamine (1887); Paranitraniline Red (1889); Alizarin Bordeaux (1890); Alizarin Green (1895). At the present time it may truly be said that the dyer is furnished with quite an embarrassing number of coal-tar dyestuffs which are capable of producing every variety of colour possessing the most diverse properties. Many of the colours produced are fugitive, but a considerable number are permanent and withstand various influences, so that the general result for some years has been the gradual displacement of the older natural dyestuffs by the newer coal-tar colours. Entry: A