(Un)healthy relationships: African labourers, profits and health services in Angola's colonial-era diamond mines, 1917-75.

The Companhia de Diamantes de Angola, or Diamang, mined for diamonds in colonial Angola from 1917 until independence in 1975. The enterprise's Health Services Division (SSD) was responsible for supplying mine managers with an African labour force comprised of healthy, and therefore productive, employees. In practice, though, this otherwise 'healthy' system did not always work. While SSD personnel attempted to fulfil their charge by implementing a series of screening measures, production targets and a scarcely-populated regional labour pool regularly prompted senior officials to compel the SSD to clear recruits who were otherwise unfit for mine service. Drawing upon interviews with former SSD staff and African labourers, as well as company and colonial archival sources, this article focuses on the interplay over time between the SSD, the company's production demands and these labourers.

Minors in name only: child laborers on the diamond mines of the "Companhia de Diamantes de Angola" (Diamang), 1917-1975.

Although African men and women comprised the vast majority of the labor force on Angola's colonial-era diamond mines, child laborers, or "minors," also played important roles, primarily as mineworkers and plantation laborers. While these young male and female laborers' daily tasks were often lighter than those assigned to adult males, they often worked side-by-side with more senior workers and were equally subject to physical abuse, poor rations, and injuries. Similarly, minors also employed many of the same strategies as their more senior coworkers to better their lives. Their experiences suggest that these young laborers were minors in name only.

[The diamond saga: from Moissan to the present day]. / La saga du diamant: de Moissan à nos jours.

Diamond synthesis by Moissan brought about fierce controversies and harsh criticisms. Our purpose is not to settle the debate but to show that many criticisms were not as rigorous as it could be expected from scientific arguments. We will briefly describe how diamond synthesis developed towards methods that make Moissan's work appears as quite reasonable. The paper concludes with a tribute to Moissan, Hannay and Burton who opened the way towards modern diamond synthesis and the predicted revolution of the semiconducting diamond.

The rise and fall of the jewel microscope, 1824-1837.

To increase the resolution of the microscope Sir David Brewster proposed that lenses should be made from materials of high refractive index. In 1824 Dr C.R. Goring commissioned Andrew Pritchard to make a diamond lens, which was delivered at the end of that year. Pritchard made other jewel lenses and devised a stand for use with them. Inhomogeneities in the gem stones and the improvements in the design of objectives published in 1830 by J.J. Lister, led to the abandonment of jewel lenses for microscopy. The properties of twelve jewel and two fused quartz lenses have been measured and are tabulated.