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.

Surface acidity of almost homoionic montmorillonites was measured by titrating selected Hammett indicators adsorbed on the clay with n-butylamine.

As expected, the acidity is strongly affected by the exchangeable cations and the degree of hydration of the clay. Greater polarizing ability of the interlayer cations increases both the strength and number of acid sites per H0 value. The acidity of ‘activated’ or heated H-montmorillonite does not exceed that of untreated H-montmorillonite. The origin of the negative charge in the montmorillonite appears to affect the acidity of the clay.

It is concluded that the very high acidities reported in the literature (H0 < −5·6) are apparent only and are due to physisorption of the indicator.

A series of Cu(II) reduced charge montmorillonites (RCM) of varying charge reduction has been prepared by exchange of the parent Li(I)-Na(I) mineral with CuCl2 in 95 per cent ethanol solution. The Cu(II) exchange capacity, as determined by Na(I) exchange in 1:1 (v/v) ethanol-water, is a linear function of the fraction of Li(I) initially present on the exchange sites, F. Selective Cu(II)-saturation on internal and external sites was achieved at maximum charge reduction (F = 1.0). Water sorption isotherms and (001) basal spacings are interpreted in terms of an increasing tendency toward interlayer collapse with increasing charge reduction. Because of the higher hydration energy of the Cu(II) ion, however, the fraction of non-expansible interlayers at a given F value is lower than those present in the corresponding Li(I)-Na(I) RCM. Electron spin resonance spectra of oriented samples show that under air-dried conditions (ca. 40 per cent r.h.) the predominant Cu(II) species present, whether on internal or external sites, is the planar Cu(H2O)2+4 ion. The symmetry axis of the ion is oriented perpendicular to the a-b plane of the silicate sheets. In the presence of a full partial pressure of water, the Cu(II) ions on the external sites and those which are in expansible interlayers become totally hydrated Cu(H2O)2+6 and tumble rapidly. The Cu(H2O)2+4 ions in non-expansible layers retain their restricted orientation on the silicate surface. Some general conclusions have been drawn regarding the nature of charge distribution in the mineral.

Full and reduced charge smectite saturated with Na(I), Ca(II), Cu(II), or tetralkylammonium ions were swollen by a series of solvents of various bulk physical properties. In the full charge smectites, swelling occurred in all solvents regardless of the exchange ion or the initial water content. Charge differences did not usually result in differential swelling of the smectite. Little correlation was found between the degree of swelling and the Gutmann donor numbers, bulk dielectric constants, bulk surface tensions, or dipole moments of the solvents. The intensities of the high field Fe(III) resonance (g = 3.6) in the esr spectra of full charge smectite swollen in various solvents reflected variability in exchange ion positions and depended upon the Gutmann donor number of the solvent. Considerable variety in the stereochemistry of Cu(II)-solvent complexes was revealed by esr spectra of the swollen systems.

Glauconite has been synthesized at low temperature by precipitation of Fe-hydroxides from Si-, Fe-, Al-, and K-containing solutions under reducing conditions. The compositions favorable for the synthesis at 20°C and pH 8.5 are 1 ppm Fe, 0.15 ppm Al, 13 ppm Si02, 1000 ppm KC1, and 1000 ppm dithionite. The K-content of the solutions must be sufficiently high to fix K in the precipitate.

Under special early diagenetic conditions glauconite is formed in marine sediments, probably at the interface between reducing and oxidizing zones in the muddy sediments. The silica content of pore waters seems to control the formation of glauconite or chamosite rather than depth or temperatures of the bottom waters.

Pān-toh is an ancient practice of collaborative roadside banquet in Taiwan, in which participants temporarily occupy a public space, arrange the meal and enjoy the anarchic feast. Although this custom has declined in frequency as a result of capitalist developments, the idea has seen a nostalgic revival in the past decade amidst international military tensions and domestic ideological battles. It has been appropriated into artistic productions to demonstrate an activist gesture of minority alliance that reflects the (post)colonial histories and reticent survival tactics therein. This essay takes Gather Theatre Group's Twelve Dishes Ballad as an example, to see how the pān-toh performance allegorized a reparative solidarity that departed from the paranoid interpretation of political scenarios and moved forward to a non-violent practice that emphasizes underground mutual dependence and intervulnerability. This apparatus of solidarity, nourished by Taiwan's experiences, contributes to a critique of the currently prevalent tendencies of defensive protectionism.

The mechanism of interaction between cationic organic molecules satisfying exchange sites in montmorillonite and organic molecules with carbonyl groups was investigated. Dialkyl amides adsorbed on trimethyl-ammonium- and tetramethylammonium-montmorillonite were studied by i.r. spectroscopy. The electronegativity or basicity of the amides, expressed as a summation of the Taft polar factors (Σσ*), was found to be linearly related to the C-O stretching frequency after adsorption on trimethyl-ammonium-montmorillonite. Furthermore, the changes in the C—O and N—H stretching frequencies of the amides and trimethylammonium ion respectively, exhibited a direct linear relationship. Thus, the dialkyl amides were shown to be hydrogen bonded through the oxygen of the carbonyl group to the hydrogen of the trimethylammonium. The (001) spacing of trimethyl-ammonium-montmorillonite was 12·9 Å Only after the adsorption of amide molecules of the size of N,N-diethylacetamide or larger did this spacing change. Dialkyl amides were adsorbed on tetramethylammonium-montmorillonite, but less energetically than on trimethylammonium-clay. The (001) spacing of tetramethylammonium-montmorillonite was 13·8 Å and remained the same after adsorption of the dialkyl amides. Evidence of hydrogen bonding between the hydrogen of trimethylammonium-ion and some other carbonyl compounds was also noted.