One of the most dramatic advances in the physical sciences during the nineteenth century was the emergence of spectroscopy. It rapidly became an invaluable experimental technique for chemists and astronomers, while for physicists it opened a window upon the world of sub-atomic phenomena. Sir John Herschel played an important part, the value of which has sometimes been underestimated, in the early development of spectroscopy. This paper examines his contribution to the subject during the period 1819–61 in the light of his (...) publications and of certain manuscript material preserved in the Royal Society's Library. Herschel corresponded with most of the scientists who did important work in spectroscopy during his lifetime, and he expressed definite opinions on most of the practical and theoretical problems that arose in it; however, the present study cannot pretend to offer a complete discussion of all aspects of the early history of spectroscopy. (shrink)

Drawing on Peter Harrison's argument that individuals should be attributed a central role in analyses of the relationship between science and religion, this article proposes that an understanding of personality can help us better appreciate a person's attitudes to both science and religion. Rather than seeing an individual's attitudes to these two topics as separate, if sometimes overlapping, parts of their lives, it is suggested that both may result from psychological drives and sometimes from the same psychological drive. Two contrasting (...) case studies are employed to illustrate this proposal. First, Paul Dirac who, it is argued, was on the autistic spectrum, a personality profile that is often linked to both mathematical physics and atheism. By contrast, Michael Faraday's scientific practice and his commitment to a specific form of Christianity were underpinned by his need for security, as assured by the God‐given laws that operated in both the physical and moral domains. (shrink)

SummaryFaraday's concept of force is described by six assumptions. These specify a concept that is quite distinct from ‘mechanical’ conceptions of his contemporaries and interpreters. Analysis of the role of these assumptions clarifies Faraday's weighting of experimental evidence and shows how closely-linked Faraday's chemistry and physics were to his theology. It is argued that Faraday was unable to secularize his concept of force by breaking the ties between his physics and his theology of nature. Examination of his basic assumptions also (...) explains Faraday's failure to quantify his principle of conservation of force, his rejection of mechanical concepts of force and energy, and his early attempt to develop a wave-model for the conversion and transmission of electricity, magnetism, light and heat. (shrink)

In June 1849 William Thomson wrote to Michael Faraday suggesting that the concept of a uniform magnetic field could be used to predict the motions of small magnetic and diamagnetic bodies. In his letter Thomson showed how Faraday's lines of magnetic force could represent the effect of the ‘conducting power’ for magnetic force of matter in the region of magnets. This was Thomson's extension to magnetism of an analogy between the mathematical descriptions of the distribution of static electricity and of (...) the diffusion of heat through uniform bodies. In 1850 Faraday published his first comprehensive theory of the magnetic properties of matter. He explained the behaviour of matter in the field by four assumptions: that matter has a specific disturbing effect on the normal distribution of lines of magnetic force; that this effect depends on its ability to conduct or transmit the magnetic action; and that material bodies tend to move so as to cause the least possible disturbance of the lines from their normal distribution. Faraday also assumed that diamagnetics transmit magnetic action less well than empty space, while paramagnetics transmit it more readily than space. This implied that space must have a specific conductivity between that of paramagnetic and diamagnetic materials. In order to preserve a distinction between matter and space Faraday defined ‘matter’ as either the source of action or as a conductor which is able to influence the lines of action; space was the absence of such powers. While space could conduct, it differed from matter in that it could neither originale lines of force nor influence their course and distribution. (shrink)