1878 illustration of solar and sidereal spectra using astronomical spectroscopy techniques to measure the spectrum of electromagnetic radiation. At this time the study was described by John All Gladstone, FRS, who was President of the British Chemical Society and also President of the Physical Society. Apart from chemistry, he undertook pioneering research in optics and spectroscopy. He indicated how the whole of the knowledge of the chemical nature of the Sun and other astronomical bodies had only been obtained during the last twenty years. It explained in a few words how the rays of light from an object can tell us what it is composed of.