Professor Thomson had been a typical Scottish ‘lad o’ pairts'. Deservant of repute as teacher, scientist, editor and historian, his most distinctive achievements were in scientific journalism and propaganda. These were powerfully exhibited in the interests of Dalton's Atomism and of Prout's Hypothesis—and in university politics.

His work for Chambers' Encyclopaedia and for Nicholson's Journal was influential and effective. His textbooks gained an international esteem and each successive edition was kept up to date.

Much of his professional outlook and experience is expressed in his History of Chemistry (2 vols. 1830–31). Researches in his old Department at Glasgow on his choice and use of material provide the main topics of this Address. These volumes are still important.

The exploitation of the lead resources of this country by the Romans commenced very soon after their arrival and shows every sign of being a well organized trade. Little evidence of deep mining has survived and it is probable that most of the ore was obtained by means of shallow workings, mainly in Somerset, Salop, Flintshire and Derbyshire. Although the silver content does not seem ever to have been as high as that of some well-known mines in the Mediterranean, it is clear that silver has been extracted by the Romans from some of the British lead. The lead was cast in carefully made moulds, producing pigs with inscriptions which indicate their date. These were then used for the pipes, cisterns and pewter tableware which contributed to the high standard of living of the period.

In 1661 Gerard Kinckhuysen published at Haerlem an introduction to algebra written in Dutch. Because of the clarity and compactness of its presentation it was considered suitable for dissemination to a wider class of readers than those able to read Low Dutch. Nicolaus Mercator, a wellknown mathematician of German origin, who had come to England as a young man in the later 1650s, was asked by Lord Brouncker to prepare a Latin translation of it. To this Isaac Newton, at the request of Isaac Barrow and John Collins, added explanatory notes and comments, and the manuscript was sent to Collins in London on 11 July 1670. Newton's draft, though still unpublished, is preserved, but Mercator's original translation was believed to have been lost. Only recently I rediscovered it in the Bodleian in a bound volume deriving from the estate of the Oxford mathematician John Wallis, which contains several books and pamphlets once in his possession.

This article is divided into four sections:

I. A survey of Kinckhuysen's Algebra ofte Stel-konst.

II. A summary of Newton's notes and additions to it.

III. An account of the unsuccessful efforts of Collins and Newton to publish the Mercator translation, enlarged with Newton's comments—this is abstracted from Collins' correspondence with Newton, Wallis and Gregory.

IV. A description of the volume now in the Bodleian Library, press-marked ‘Savile G. 20’, which has Mercator's translation interleaved with the printed Dutch original and bound with other books once owned by Wallis.

Through the years there have been subtle changes in the evaluations of the work of Tycho Brahe. As one examines the tracts dealing with novae and comets in which reference is made to the nova of 1572 or the comet of 1577, it becomes quite evident that in different parts of Europe and in the Near East and at different periods of time and among men of different religious convictions different values were placed on his work. The extent of his influence should be distinguished from the measure of his achievements. Moreover, his importance cannot be completely separated from that of Kepler and the horde of other writers who furnished more than a mere background for the display of Tycho's brilliance. Here, as always, there is the danger of assigning to one man innovations that were, so to speak, in the air.

The Geological Society of London was the first learned society to be devoted solely to geology, and its members were responsible for much of the spectacular progress of the science in the nineteenth century. Its distinctive character as a centre of geological discussion and research was established within the first five years from its foundation in 1807. During this period its activities were directed, and its policies largely shaped, by its President, George Bellas Greenough, on whose unpublished papers this account is chiefly based.

The Society began as a small scientific dining club in London, but it developed rapidly into a learned society with a nation-wide membership. It became so independent in outlook and so active in research that it was felt to threaten the esteem of the Royal Society; and little more than a year after its foundation it clashed with the Royal Society (and especially with its President Sir Joseph Banks) so violently that its continued existence was for a time uncertain.

Its development into a large independent society was the outcome of its ‘Baconian’ view of the importance of collecting geological facts as a surer basis for geological theories. For this purpose it initiated an ambitious scheme for co-operative research, which would unite the efforts of ‘philosophers’ with those of ‘practical men’. Only personal reasons seem to have kept the most prominent of the practical men—William Smith—from co-operating with the Society.

Scurvy is now almost a forgotten disease, but it would be difficult to exaggerate its importance in the history of a maritime nation such as our own. To the historian of medical science it is equally interesting, because the various and extraordinary variety of theories concerning it reflect in themselves the intellectual climate of the past. By their repeated refusal to accept the conclusions of an experimental method, by their pedantic reliance on a priori reasoning or antiquated prejudices, the medical authorities of all countries delayed the conquest of this terrible disease long after a cure had been established by men who had practical experience of it. If anyone imagines that even in scientific knowledge progress is inevitable, let him remember that scurvy continued to be the curse of the sea and the hardship of explorers so recent as Scott and Shackleton a hundred years after it had been eliminated in the fleets of Nelson's day.

A eudiometer formerly believed to have belonged to Henry Cavendish was probably made after his death. It may have belonged to John Dalton.