LUMINOUS SHOWERS. 157 



phorus, and, when it becomes clear, pour into a bottle with a 

 glass stopper. When it is to be used, take out the stopper, 

 and admit the air. The oil can be used with a brush, and in 

 the dark will appear luminous. 



Water may be rendered phosphorescent by dissolving a 

 small piece of phosphorus in ether for several days in a glass- 

 stoppered bottle ; then by immersing a piece of sugar in the 

 solution, and placing it in water, the latter becomes vividly 

 phosphorescent. It should be remembered that phosphorus 

 and ether are both extremely dangerous, and experiments 

 with them should be conducted with care and judgment. 



While this is a mere toy, luminous paint is of great 

 value. It is easily made, and can be applied to many pur- 

 poses. 



Schade of Dresden has quite recently patented an inven- 

 tion, which enables him to produce paints that are luminous 

 without affecting the tint by day. This is accomplished, 

 according to the inventor, as follows : 



Zanzibar or Kauri copal is melted over a charcoal fire. 

 Fifteen parts of the melt are dissolved in 60 parts of French 

 oil of turpentine, and the filtered solution is mixed with 25 

 parts, previously heated and cooled, pure linseed-oil. The 

 varnish which is thus obtained, is used in the following 

 methods, in the manufacture of luminous paints, by grinding 

 between granite rolls in a paint-mill. Iron rolls should be 

 avoided, because particles of iron, which are liable to be 

 detached, would injure the luminous properties. 



Varnishes, as they occur in commerce, generally contain 

 lead or manganese, which would destroy the phosphorescence 

 of calcium sulphide. A pure white luminous paint is prepared 

 by mixing 40 parts of the varnish obtained in the above- 



