3(J4 Misce/laiicuus InteUigeiue. 



put large wires of copper or silver, or small ones of gold, hori- 

 zontally into a steady flame of alcohol. The colours will appear 

 on the part at the flame, in the order mentioned, and pass out- 

 wards as the heat is conducted along the wire. In each metal 

 that tint is most vivid which is like its own colour, and that 

 least which is dissimilar to it. On iron the blue is bright and 

 clear, whilst the purple is languid, and approaches to violet : 

 on gold made into fine wires, the yellow is very bright : on cop- 

 per the red and purple are fine, and the blue always light ; on 

 silver all the colours are equally lively. The best method of 

 shewing the order of the colour is to place a piece of common 

 tin-plate, very clean and bright, over the steady flame of a lamp. 

 At first, a bright circle of fused tin is formed on the part just 

 over the flame, in the middle of which a circle, of a gold yellow 

 colour, soon appears, which, expanding, has, at last, a violet 

 spot in its centre ; this also expands outwards, and a blue tint 

 forms in it, which, if also allowed to extend itself, the action of 

 the flame being continued, will have the middle part converted 

 into a whitish red scoria. 



In certain circumstances, the successive reproduction of the 

 same colours may be caused in the same order. Thus, after the 

 light blue of the first series, follows yellow, then purple, then 

 deep blue, and then again yellow, and so on. These successive 

 series may be obtained on wires of silver, copper, and gold, 

 heated by the flame of alcohol, and also on laminae of steel, by 

 means of hot charcoal. But the following is the best method 

 to obtain many distinct series : 



If thin leaves of copper or brass (Dutch metal,) be exposed to 

 the flame of alcohol, so as to melt them, they readily burn. Care 

 must be taken that only part of the leaf is burnt ; this part re- 

 tains its original form, but has become transparent. In all those 

 places between the burnt and the metallic part will be produced 

 parallel fringes, of very bright colours, which, when observed 

 by a lens, present three or four series, in the order already 

 mentioned. A small flame of hydrogen, forced from a bladder, 

 through a fine tube, against a thin plate of silver, so as con- 

 stantly to touch it in the same spot, gave systems of coloured 



