In this paper we examine the study of minerals from the Renaissance to the early nineteenth century in the light of the work of Michel Foucault on the history of systems of thought. In spite of a certain number of theoretical problems, Foucault's enterprise opens up to the historian of science a vast terrain for exploration. But this is the place neither for a general exegesis nor for a general criticism of his position; our aim here is the more modest one of taking certain points from Foucault's study, The order of things, and seeing how far they can be extended into an area not explicitly considered in that work.

The term ‘Ohm's law’ traditionally denotes the formula of Georg Simon Ohm relating voltage, current, and resistance in metallic conductors. But to students of sensory physiology and its history, ‘Ohm's law’ also denotes another relationship: the fundamental principle of auditory perception that Ohm announced in 1843. This aspect of Ohm's science has attracted very little attention, partly because his galvanic researches so thoroughly eclipsed it in success and importance, and partly because Ohm's work in physiological acoustics had so little immediate impact on the science of his time. On announcing his hypothesis in 1843, Ohm found himself drawn into a bitter dispute with the physicist August Seebeck, who successfully discredited the hypothesis and forced Ohm to withdraw from the field.

The history of science can be approached in several different ways. It may be studied, as in the classification once favoured in the long-established Department of History and Philosophy of Science at University College London, by considering separately the history of individual sciences: physics, chemistry, biology, etc.—Partington's monumental History of chemistry is a good example of the cross-section of history of science obtained by considering a single discipline. This approach is understandable when history of science is the work of retired specialists in a particular science. On the other hand, many of those who have approached the history of science from a training in general history have tended to favour a study of a particular period as an alternative to an orientation by subject. This is particularly valuable before the nineteenth century, when subject boundaries were not so tightly drawn as some of the old science historians tended to assume. A third possibility is area studies, usually the history of science within a particular country. Sometimes this is done unconsciously, as when historians claim that they are dealing with a general theme, such as science and religion or scientific institutions, but do so with special reference to their own country. French historians of ‘the Enlightenment’ often study French authors exclusively. Language as much as country is a limiting factor here.

The purpose of this article is to point out that, contrary to popular belief, David Gregory did not lecture on the Newtonian philosophy when he was Professer of Mathematics at Edinburgh University. This belief has arisen because of a statement of Whiston's which attributes to David a paper written by his younger brother James. Nevertheless, some of David's Edinburgh students were acquainted with Newton's work, and I shall examine the extent to which this was so, and look at the other sources which he used in his teaching. Finally, Gregory's attitudes are seen to be typical of those prevailing in the Scottish universities of his day.

Even at the level of the most elementary arithmetical operations, procedures and practices change. During the twelfth and thirteenth centuries an unusually well documented development took place: at the beginning of the period the authors of elementary manuals of computation taught the use of the abacus, whereas at the end they described the method of calculation which came to be known as the algorism. Their ideas about number, however, were still largely drawn from Boethius's rendering of Nicomachus of Gerasa's Introduction to arithmetic in the Arithmetica and there had been little progress in attempting to reconcile Boethius's teaching on the theory of number with the rather different assumptions that underlie the methods of practical calculation. Boethius and Nicomachus, for example, emphasize that one is not a number but the source of number, and they are aware of the special problems posed by ‘two’. Nicomachus questions whether ‘two’ is anything more than an embodiment of the principle of ‘otherness’; for him, it is open to dispute whether it can be rated a number in its own right. For the teacher of the skills of calculation, ‘one’ and ‘two’ are merely digits like any other. By the fourteenth century, collections of textbook material on elementary arithmetic provided the student with instruction in both theory and practice. The abacus manuals are missing from many such collections because by then the abacus has apparently been relegated to the status of a simple practical aid, but the other elements in medieval arithmetical studies are variously covered.

As a natural philosopher, Count Rumford is best known for his vehement advocacy of a motion or mechanical hypothesis of heat and for the dramatic experiments that he performed to support this hypothesis. Although a motion hypothesis which held that heat was merely the motion of the ultimate particles of a body had a distinguished history, with advocates that included Bacon, Boyle, Hooke, and Newton, most British natural philosophers by the beginning of the nineteenth century believed that the phenomena associated with heat were caused by an imponderable fluid. William Henry reflected contemporary opinion in 1803, when he wrote:

The former of these opinions [i.e. the existence of caloric], though far from being universally admitted, is now generally received; and the peculiar body, to which the phenomena of heat are referred, has been denominated by M. Lavoisier [as] caloric.

The twelfth-century school of Chartres has long been famous for its rhetorical excellence and its Platonist philosophy. Only recently, however, have scholars become aware of the important role played by natural science in this centre of European thought. Questions about the corporeal world, or, as one Chartrain put it, ‘those things which are and which are seen, were asked there just as frequently and their answers sought just as eagerly as more intangible queries about incorporeal beings. Chartres produced long encyclopedic works of natural philosophy and applied a scientific outlook to its theological writings as well.

Central to the development of geology has been the growth of systematic empirical observation as a programme of scientific practice. Fieldwork has focused on many objects—strata, fossils, and landforms—and has issued in a variety of products, such as maps, sections, and monographs on regional geology, particular rock formations and fossils. Early in the nineteenth century, above all, many influential geologists sought to define their science as one exclusively of field observation, description, and the accumulation of data. The rise of fieldwork, in Britain as elsewhere, is an important phenomenon in the making of geology. It must be explained.

In The life of Richard Owen by his grandson there is an inference to the effect that Owen had objected to his name being used to authorize various statements that Whewell was drafting in opposition to the Vestiges. The inference is drawn from letters that Whewell wrote to Owen on 13 and 15 February 1845. Corroboration of this would corne from a letter of Owen to Whewell, dated 14 February 1845, if extant. Among the Whewell papers at Trinity College, Cambridge, there are several letters from Owen to Whewell, none of which bears that date. There is one, however, dated 14 February 1844 which, on doser inspection, turns out to be the missing link in their correspondance. The evidence for the misdating is not merely that the letter falls naturally into a later sequence. The conclusion is inescapable because Owen refers to an ‘opinion which I have always entertained, and still do strongly, on the subject of a refutation of “Vestiges”’. Since the first edition of Chambers's book did not appear until October 1844, the letter must belong to the following year. My object in this paper is to examine the implications of this letter for a reconstruction of Owen's attitude to that book which Adam Sedgwick could so detest for, among many things, its ‘gross (and I dare to say, filthy) views of physiology’.