Category: Science - Chemistry/Biochemistry
=Colour.=--The term “colour” is inappropriately given by common usage to material substances which convey a sense of colour to the human eye, but is properly restricted to that sense itself. The material colour should be called “pigment” or “dyestuff” in the raw state, and pai...
=Colour.=--The term “colour” is inappropriately given by common usage to material substances which convey a sense of colour to the human eye, but is properly restricted to that...
14. CHAPTER II.Several manufactured carbonaceous substances are known in commerce under the generic name of “Blacks.” The most important of these are animal-black, bone-black, Frankfort-black,...
15. CHAPTER III.=Cobalt Blues.=--Some of the compounds of cobalt with alumina, phosphoric acid, silica, and tin, are remarkable for possessing a fine blue colour of great permanency and indestr...
16. CHAPTER IV.Brown colouring matters are obtained from all three kingdoms--the animal, the vegetable, and the mineral--but in greatest abundance from the last named. The natural mineral brow...
17. CHAPTER V.Green pigments form an important and numerous class, but many of those which possess the most brilliant and durable qualities contain highly poisonous ingredients, and some of t...
18. CHAPTER VI.Though the red pigments are an important class, they are not numerous, and, with the exception of a few lakes, they are drawn from the mineral kingdom. The most useful are compo...
19. CHAPTER VII.In the whole range of pigments there is no more important class than those to be described in this chapter. Not only are the white pigments largely employed for the sake of thei...
20. CHAPTER VIII.The yellow pigments do not form a large or important group, and beyond a few organic colouring matters which have a limited use in artistic painting, they are chiefly confined t...
21. CHAPTER IX.(_a_) To a filtered solution of the colouring matter is added a solution of alum; the whole is agitated, and the colour is precipitated by a solution of carbonate of potash.
22. CHAPTER X.The luminosity of minerals has an obvious practical value in the case of such substances as can be conveniently applied in the form of a paint to surfaces which are alternately...
23. CHAPTER XI.Besides the chemical tests for purity and adulteration, which necessarily must vary with each pigment, there are certain other examinations which partake rather of a mechanical...
24. CHAPTER XII.Paint consists essentially of two parts, the pigment (see Chapters I. to VIII.), and the vehicle or medium. In the case of oil paints, a third substance termed a dryer becomes n...
25. CHAPTER XIII.In Fig. 40 is shown a complete set of paint grinding and mixing machinery, made by Wright & Co., 157 Southwark Bridge Road, London, S.E., which has given highly satisfactory res...
26. CHAPTER XIV._The Surface._--Of whatever the surface may be to which the paint is to be applied, great care must be taken that it is perfectly dry. Wood especially, even when apparently dry,...