Colour brightness

Leaf colour Bright green Light green... 

Observation should be made of the colour, brightness, smell and taste of the sample Of especial importance is tasting, which, to an expert, may give valuable indications concerning the quality of the product. 

Origin Idaho Experiment Station, USA Jonathan X Wagener cross Ripening beginning of October, do not pick too early Fruit medium size to large, colour bright red... 

Properties.—In groups of slender prismatic crystals also columnar, massive, resembling stibnite. H. = 2-0. G. =4-81. Lustre metallic. Colour bright lead-gray. Streak red. 

Non-soap greases using finely divided solids as thickeners are useful as lubricants at elevated temperatures. Materials used include organO Clays such as dimethyldioctyl-decyl-ammonium bentonite (Bentone greases) or selected dyestuffs which produce brightly coloured greases. 

Phthalein reaction. Fuse together carefully in a dry test-tube a few crystals of phthalic acid or of a phthalate and an equal quantity of ph tol moistened with 2 drops of cone. H2SO4. Cool, dissolve in water and add NaOH solution in excess the bright red colour of phenolphthalein in alkaline solution is produced. 

The contents of B, which act as a control, are treated with mercuric chloride in order to inhibit the action of the enzyme, and then 10 ml. of urease solution are added. The solution is diluted with water and ammonium chloride added (in order to balance the ammonium chloride subsequently formed in A). Meth) l-red is then added and the solution is titrated with Mj 10 HCl from a second burette B until a bright red colour is obtained. 

Transfer 30 g. of the hydrochloride to a 500 ml. separatory funnel, add 100 ml. of water and shake until a thin paste of uniform consistency is obtained add 10 per cent, aqueous sodium hydroxide solution in the cold with shaking until the whole mass has become bright green (the colour of the free base) and the mixture has an alkaUne reaction. Extract the free base by shaking with two 60 ml. portions of benzene (1). Dry the combined benzene extracts with a Uttle anhydrous potassium carbonate, and filter into a distiUing flask fitted with a water condenser. Distil off about half of the benzene, and pour the residual hot benzene solution into a beaker. Upon cooUng, the p-nitrosodimethylaniUne erystallises in deep green leaflets. Filter these off and dry them in the air. The yield of p-nitrosodimethylaniUne, m.p. 85°, from the hydrochloride is almost quantitative. 

Nickel (II) phthalocyanine [14055-02-8] M 571,3, m >300 , Wash well with H2O and boiling EtOH and sublime at high vacuum in a slight stream of C02. A special apparatus is used (see reference) with the phthallocyanine being heated to red heat. The sublimate is made of needles with an extremely bright red lustre. The powder is dull greenish blue in colour. [J Chem Soc 1719 7936.]... 

Also of interest are salts of melamine (see Chapter 24). In the nylons these can be used with bright colours (unlike red phosphorus) and do not adversely affect electrical properties. They do, however, decompose at about 320°C. Similar materials are very important in giving flame-retardant properties to polyurethane foams. 

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