Chemical analysis of the Sun

We can not get the substance out of which consist of stars, and expose it to direct chemical research. But their light is available to us, and for its properties, we can make certain conclusions about the bodies that it emits, and through which it passes. Conclusions obtained in this way, just the same as those in which leads us to a laboratory analysis - direct dissolution and precipitation of the substance or test it before the blowpipe flame. Under the refraction of light of course deviates from the rectilinear direction, experienced when moving from one transparent medium to another. If, for example, the light beam passes from air into glass or water, it changes its original direction. Evidence can serve as a phenomenon, observed when lowering the stick into the water: submerged part seems bruised on the border with her part in the air. Newton first showed that the rays of different colors have different refrangibility. If we run them through trihedral glass prism, we note that the deflection of the test of the refraction is very different. Red is refracted weakest, orange a bit more yellow, green, blue, even more, and finally, a maximum refractive power has a purple color. It is known that ordinary white light consists of rays of different colors, passing through the prism of flint glass, the different rays are not refracted equally, and the light splits, and if it falls on the white surface, then we get a motley band consistently painted in colors: red, orange, yellow, green, blue, indigo, violet. This band is called the spectrum. Triangular prism makes it possible to determine the composition of all light. For these studies used a special device which is known as a spectroscope, the instrument that allows us to observe phenomena with remarkable precision. Device it is shown in Fig. 108. In one of the tubes is thin slit through which light enters and, through the collective lens light, released from a pipe thrown by one of the faces of the prism at the center of the instrument, another tube is used for observing the resulting spectrum. This simple device is the device in special cases mutates and becomes more complicated: instead of a prism used more and thus cause a stronger refraction, sometimes attached devices, allowing to observe two different sources of light simultaneously and compare them. If we will examine the light emitted by incandescent white-solid and liquid bodies, and pass it to this through the prism, we note that it is in all cases the same and it always gives a full and continuous spectrum, contains all the colors. Otherwise observed in the study of a passionate gases: the spectrum of visible light bands separated by dark intervals; old monotony is not noticed: each gas makes its own and in all cases the same spectrum, but differs from those of other gases. Thus, we are able to determine the chemical nature of gases and vapors through the direct study of the light emitted by them. This is the essence of the spectral analysis. If such experiences do with some sodium compounds, such as table salt (sodium chloride), the weak instruments noticed a bright yellow line in strong - two. This reaction is extremely sensitive, with her help can be proved by the presence of one of the three million milligrams of sodium, such precision does not have any other chemical method. Enough to pull the plug about bunzenovoy burner to the field of view of the pipe appeared yellow sodium line: the surface is covered with his hands afterwards, which encompasses, among other things, and sodium chloride, the last speck rebounds for stroke and falls into the flames. Very common in nature, but the found small amounts of lithium metal gives a weak yellow and very bright red line, and in this case the reaction is very sensitive and allows us to prove insignificant traces of the element. Some mineral waters are enjoyed as a healing agent, contain a lithium salt, if you drink this water, then draw a drop of sweat under running a piece of paper and burn the latest, the ashes can prove the manner described the presence of lithium. The extraordinary sensitivity of the method made it possible for chemists to discover some of the elements found in nature in trace amounts, and until then unknown; Bunsen discovered two close to the metal potassium, cesium and rubidium, were later found in the same way gallium, indium, thallium and others.