Isaac Newton developed an unusual and little-known theory of subterranean metal and mineral formation by integrating concepts drawn from his own alchemical experimentation and reading with the mechanical philosophy that he inherited from other seventeenth-century figures such as René Descartes and Robert Boyle. Until recently, Newton’s geochemical theory has been known incompletely, since the primary text in which it is found, Smithsonian MS Dibner 1031B, had only been published in a fragmentary form. Thanks to the 2006 edition of the complete manuscript appearing on the online Chymistry of Isaac Newton site ( www.chymistry.org ), it is now possible to arrive at a far more complete understanding of Newton’s early theory of metallogenesis than before. The present paper provides a concise analysis of Newton’s views on this subject, showing how he integrated themes from alchemy and the better-known parts of his natural philosophy to arrive at a novel theory of the production of metals and minerals within the earth.

The time between 1640, when Álvaro Alonso Barba published his Arte de los metales ( Art of Metals ), and 1761, when Francisco Xavier de Gamboa published his Comentarios a las ordenanzas de minas ( Commentaries on Mining Ordinances ), was a transitional period in which scientific mining and metallurgical knowledge in Spanish America became operative and practical and replaced the long-standing Spanish (and European) medieval tradition of the theory of minerals and metals. Barba was the last representative of this tradition, inheriting the complex world of the classical writers, the medieval alchemists, the first news from the new American lodes, and the first steps of the Scientific Revolution. On the contrary, Gamboa did not worry about classical and medieval theories, nor did he worry about the problem of metal generation. He was concerned only about the most effective system with which to profit from mining using all the paraphernalia that the science and experience of two worlds could furnish. Both handbooks, very successful in their respective times, show clearly two different approaches to the principal question: how to best manage, from two such different perspectives, the American treasures.

Geology is among the most visual of the sciences, and spatial reasoning takes place at various scales and in various contexts. Among the spatial skills required in introductory college geology courses are spatial rotation (rotating objects in one's mind) and spatial visualization (transforming an object in one's mind). Geologic curricula commonly require students to visualize Earth in many ways, such as envisioning landscapes from topographic maps, the interaction of layers and topography, and the progressive development of geologic features over time. To facilitate learning in introductory college geology laboratories, we created two geologic modules— Visualizing Topography and Interactive 3D Geologic Blocks. The modules were developed as learning cycles, where students explore first, are then introduced to terminology and concepts they have observed, and finally apply their knowledge to different, but related problems. Both modules were built around interactive QuickTime Virtual Reality movies that contain landforms and geologic objects that students can manipulate on the computer screen. The topography module pairs topographic maps with their three-dimensional (3D) representations on the same screen, which encourages students to visualize two-dimensional maps as three-dimensional landscapes and to match corresponding features on the map and 3D perspective. The geologic blocks module permits activities that are not possible with normal paper-based curricula, such as interactively rotating, slicing into, eroding, and faulting the blocks. Students can also make the blocks partially transparent to reveal the internal geometry of layers, folds, faults, intrusions, and unconformities. Both modules encourage active participation by having students describe, draw, and predict, and both modules conclude with applications that require the students to extend and apply key concepts to novel situations. Assessment of the modules using control and experimental groups shows that the modules improved student performance on a geospatial test, that general spatial ability can be improved via instruction, and that differences in performance between the genders can be eliminated by a semester-long laboratory. “To go out into the field with a geologist is to witness a type of alchemy, as stones are made to speak. Geologists imaginatively reclaim worlds from the stone they're trapped within.” – Frodeman (1996 , p. 417).