Dissolution data on five of the six illites reported by Reesman and Keller (1968) indicate that these illites are more stable than was previously thought. The revised Gibbs free energies of formation (ΔGf0) with respect to the ‘ideal’ illite formula and the muscovite formula are

Use of muscovite formula as an indirect comparator provides a means of predicting the relative stabilities of these chemically complex materials.

The response of illite-equilibrated solution to a kaolin ΔGf0 was found in all samples in which a 7 Å mineral phase was detected by X-ray diffraction. Stability diagrams based upon the ΔGf0 with respect to ideal muscovite and kaolin formulas show a rather wide range in chemical conditions through which illites and kaolin minerals with differing ΔGf0 would be stable. However, in carbonate rocks and sea water illite is stable relative to kaolin. During the weathering of carbonates the lower pH zones in the clay-rich residuum above the carbonates favor the transformation of illite to kaolin minerals.

Various dehydroxylated micas and rectorites were acid-treated. Rectorite-type mixed-layer mineral was formed from 2M1 and 2M2 mica and random mixed-layer mineral from 1M and 1Md mica. Rectorite was formed again from dehydroxylated rectorite. The rehydration and rehydroxylation properties of dehydroxylated rectorite and 2M sericites were found to be similar.

The structure and hydration status of attapulgite clay after heating at elevated temperatures and the stability of parathion on these clays was studied. Using infrared spectroscopy and scanning electron microscopy it was found that the bound water was lost in two steps, at 250° and 450° with the first step being largely reversible. At 650°C the structure began to dissolve releasing significant amounts of Mg, and a decrease in aggregate porosity was noted. At 850°C an amorphous phase was formed bearing little resemblance to the original attapulgite. Parathion was stable on all of the preheated clays when kept at 25°C for 190 days. The reactions of parathion on the preheated clays was studied at 110°C Hydrolysis of parathion was found to be minimal. Isomerization was the main reaction occurring on the Ca-attapulgite, whereas on an organo-clay no isomerization was observed. A mechanism for the isomerization reaction is proposed which entails a distortion of the phosphate moiety of the pesticide by the oxygen of the ligand water resulting in the conformational changes necessary for the isomerization to take place. On the organo-clay such a conformation was not possible; hence no isomerization occurred.

A 1–0·2 μm fraction from a soil in the Dominican Republic was studied by X-ray diffraction combined with solvation, cation saturation, and heat treatments. I.R., thermal (DTA, TGA) and chemical analyses were also made. This soil is saline and alkaline and its mineral composition is greatly influenced by the lacustrine parent material and poor drainage.

In addition to swelling chlorite, illite, kaolinite, carbonates and quartz are present in the 1–0·2 μm fraction. The swelling chlorite expanded to over 18 Å when Mg saturated and solvated with glycerol or water. Lower spacings with other cations and ethylene glycol were observed. 1 N HCl treatment partially removed the interlayer hydroxides in the chlorite and 6 N HCl destroyed the mineral. The mineral gave a reflection close to 14 Å up through 600°C but collapsed at higher temperatures to 10·2 Å.

Neutron diffraction measurements for a preferentially oriented aggregate slab sample of deuterated Na-montmorillonite from Upton, Wyoming, are described for a series of clay-water contents ranging from 0 to 500 mg/g. A neutron wavelength of 2.39 Å was used with extended detectors to collect much of the “out of plane” component of the diffraction peak intensities.

The diffraction pattern intensities from the 00ℓ planes of the clay, corresponding to a reflection geometry, are a strong function of sample water content and show a variation in basal spacing from 9.8 to 19.0 Å. The hk reflections from transmission geometry measurements show, however, that the lattice a and b axes are constant within experimental uncertainty (0.02 Å) over the range in water content and their intensities vary only by a few percent. In this geometry, a broad, water-like diffraction pattern was noted as a background under the usual hk peak intensity series. This underlying water-like pattern varies in proportion to the sample water content.

Data reduction steps included consideration of background removal, multiple scattering, flux normalization, and attenuation of scattering due to sample thickness. Analysis of the reduced data revealed that the clay-water has a “liquid-like” ordering, with a density increase of approximately 5% over bulk water. An association between a few interlayer water molecules and the silicate superstructure is indicated by the slight change in the hk band intensities, but this change seems to be complete at water contents below 100 mg/g. Fourier analysis of the basal peak series from the dry clay shows that the hydrogens of the lattice hydroxyl groups lie in the same basal plane as their associated oxygen atoms.

A laboratory study of cadmium exchangeability revealed large differences in extractable cadmium which are dependent on the exchange solution being utilized. The standard exchange solutions employed in this study were: N NaNO3, N NaOAc, N NH4OAc, NCaCl2, and 2N CaCl2, in order of increasing Cd removal. An interpretation of the chemical behavior of Cd and an experiment with mixed sodium nitrate and acetate solutions suggest that cadmium carbonate, octavite, was precipitated when the sediments were saturated with Cd prior to the exchange experiments and that the quantities of Cd recovered in the acetate solutions were erroneously high because of the dissolution of the carbonate material. Dissolution of solid phases, the lack of pH buffering, and the possible formation of a complex hydroxyl chloride salt also made the Cd values obtained with the chloride solutions too high. Sodium nitrate exchange solutions minimize these problems and are thought to best represent the exchangeable cadmium in the sediment.

The adsorption of the cationic oxidized safranine S+ by a Na+, Ni2+ and Fe3+ montmorillonite has been studied with X-ray powder diffraction, u.v., visible and i.r. spectroscopy. In solution S+ may be protonated: S+, SH2+ and SH23+ have characteristic spectra in the 500–600 nm region where the clay structure does not absorb. In the Na+ as well as in the Ni2+ and Fe3+ clays, the adsorption of S+ is a cation exchange process accompanied by the protonation of the adsorbed dye such as variable concentrations of M+ (Na+, Ni2+ or Fe3+), S+ and SH2+ are simultaneously present. Protonation activity decreases from Fe3+ to Ni2+ and Na+, being the protonation site the amine group as shown by i.r. In the interlamellar space it seems that a SH2+.. S+ association exists that could be described as a sandwich structure 6.5 Å thick.

An X-ray diffraction method for determining quartz in sediments is described which is both rapid and precise, with a coefficient of variation of 1·9 per cent. Samples are ignited at 950°C prior to X-ray analysis. This removes the interference of clay peaks, increases the relative intensity of the quartz peaks and reduces the initial matrix variation of samples. The peak area ratio of quartz (4·26Å) to an added standard boehmite (6·18 Å) is measured. Quartz content is obtained from a working curve constructed using similar rocks of known free silica content, which were analysed by the method of Trostel and Wynne (1940).

The magnetic behavior of some biotite samples, from volcanic rocks of W. Thrace area, N.E. Greece, was studied in the temperature range from 85 to 270°K and compared with the chemical composition. The magnetization of the samples depends linearly on the applied field, and the magnetic susceptibility obeys the Curie law, showing a typical paramagnetic behavior which is due to Fe2+, Fe3+ and Mn2+ The effective magnetic moment was calculated from the structural formulas of the samples and deviation from the experimental values is discussed.

This article explores the sudden spate of stories concerning the so-called “blue gum negro” (the Blue Gum) that circulated in the national press from the late 1880s to the late 1890s. These reports concerned purportedly blue-gummed, Black assailants, whose bite was alleged to be poisonous, and of whom African Americans were supposedly terrified. This article argues that, although these narratives reinforced white notions of Black criminality and credulity, they marked a particular moment of racialization, in which fears of bodily contagion, generated by the recent revolution in germ theory, were harnessed to notions of embodied racial difference, to express and galvanize white anxieties about racial impurity. Because Blue Gums embodied dysgenic menace, white journalists and writers were often reluctant to disavow their existence, instead capitalizing on the slippage between figurative and literal language that characterized discourse on race. However, in appropriating Black culture and presenting a figure from folklore as a racial type, white writers betrayed not only the essentially superstitious character of racial thought but also the interwoven nature of dominant and subjugated cultures in the United States.

The misremembering by Americans of the Spanish-Cuban-American War was not an accident of either time or place. Rather, it was a collaboration between the citizenry, political and business elites, and the military-industrial complex centered on the cult of the fallen soldier. As businessmen carved up the Cuban landscape and the military occupied Guantanamo Bay, the war dead played one last service of memory. American commemoration of fallen soldiers acted as a shroud to obscure the practices of American imperialism. The recovery of the war dead thus provides an interesting example of how officials wanted Americans to remember the conflict. Most of the fallen died from disease rather than combat. Recovering the war dead thus entailed an elaborate process of sanitizing the “sick” dead and disinfecting the remains of warriors buried in foreign and tropical soil to repatriate them back to the United States. The metaphorical intersected with the medical in presenting dead soldiers from an imperialistic war with “clean and sterile bones” that would neither threaten the health of the general public nor their collective memory. Such a re-presentation would help shape how Americans remember a clean and sterile “Splendid Little War” without acknowledging the mucky details of empire-building.