A hundred years ago the science of spectroscopy, though not yet christened, may be said to have attained its majority and to be just entering on its period of full adult development. It was born, of course, with Newton's explanation of the formation of the spectrum, and for many years thereafter little of importance was added to what he had discovered. It was not, in fact, until the nineteenth century that anything of outstanding importance occurred, and then, in 1802, Wollaston (...) substituted a slit for the round hole through which Newton's sunlight passed into his prism, and thereby not only saw for the first time the dark lines in the solar spectrum but also took the first step towards the perfection of the spectroscope on which all later progress depended. The next step was taken by Fraunhofer who, in 1814, examined the spectrum through a telescope instead of letting it fall on a screen. The last essential improvement—the introduction of the collimator to make the light from the slit parallel before it entered the prism—was introduced in 1839 independently by Simms and Swan, so that before our period begins, the complete spectroscope existed, though it was not to be converted into a spectrograph, for photographing spectra, until much later. (shrink)

The publication of L. Pearce Williams's definitive biography of Faraday has led to lively discussion of the influence of Naturphilosophie on Davy and Faraday, and of the role played by Bosco vichean atomism in their scientific development. In a recent article J. Brookes Spencer argued that Boscovich's force law, involving interaction between point atoms independent of surrounding particles, was only compatible with Faraday's view of gravity and not with his views on other forces. This would of course contradict the notion (...) of unity which is absolutely fundamental to Boscovich's Theoria. (shrink)