Published online by Cambridge University Press: 14 March 2018
A focusing X-ray powder camera is described in which the degree of focusing varies with 2θ and can be made a maximum for any one reflection. It is of simple design and has two main uses:—(a) for a routine identification of the main clay mineral groups by their basal reflections, and (b) for the detection of very small amounts of any one crystalline component in a mixture.