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Practical electrosynthesis of cuprous oxide powder was carried out on a laboratory scale in a cell specially constructed both with and without a diaphragm under the various operating conditions guided by the authors' previous research. The electrolysis was appraised in terms of the quality of the cuprous oxide product, the electrodissolution of the copper anode, and the SEM microstructure of the cuprous oxide powder. In a cell having a diaphragm, of which nylon fabric is the best, the optimal electrolysis operating conditions are: 250gl−1 NaCl, 0.1–1.0gl−1 NaOH, 500–1500Am−2, 80°C, perforated titanium sheet as the cathode, and around 3% cell volume of electrolyte circulation per minute. Under these conditions a product containing more than 97% cuprous oxide can easily be produced with very stable electrolysis and quite uniform dissolution of the copper anode. To eliminate the use of a diaphragm in the cell, the addition of sodium chromate, sodium dichromate, or calcium gluconate is effective in a sense, depending upon the requirements of the cuprous oxide product. For a product in which more than 95% cuprous oxide and no copper powder are required but a slightly higher content of chloride is allowable, sodium chromate and dichromate can be proposed for use with the former around 0.03–0.05gl−1 and the latter around 0.020–0.025gl−1, although the copper anode will not be perfectly evenly dissolved. For a product in which more than 97% cuprous oxide is demanded and a very small amount of copper powder is tolerated, calcium gluconate would be acceptable at around 4.5gl−1 with quite even dissolution of the copper anode. As to the auxiliary additives, hydrazine hydrate has a negative effect on the quality of the cuprous oxide product. Sucrose can cause a small increase in the chloride content but can make the particles of cuprous oxide more compact thereby increasing sharply its apparent density. Hydroxylamine hydrochloride is the best auxiliary additive which has a positive effect on the purity of the cuprous oxide product but produces no obvious change in the microstructure on the cuprous oxide particles. Even though most work has been concentrated on the electrolytic process, the subsequent processes are equally important: 65–70°C, distilled water for washing, benzotriazole in ethanol solution for stabilization of the cuprous oxide, and 100°C at a vacuum of less than 20mm Hg for drying seem to be satisfactory. A vacuum drying temperature of 55–60°C may be more appropriate to ensure against any oxidation of the product.

Methylcyclopentadienyl manganese tricarbonyl (MMT) is effective in raising the octane level of gasoline and is currently used in Canada for that purpose in a maximal concentration of 18 mg Mn/l (slightly less than 0.07 g Mn/U.S. gal). It has been estimated that if MMT were used in all U.S. gasoline in these amounts, the median increase of Mn in ambient air would be not more than 0.05 microgram Mn/m3, with increments generally less than 0.5 microgram Mn/m3 along urban corridors. The scientific literature was reviewed to determine how the increases in environmental manganese predicted from MMT use would relate to the amounts in the natural environment and necessary to life and to the concentrations associated with toxic effects. Even with additional manganese from the use of fuel additives, total Mn intakes would remain within the range of average amounts absorbed from food and water. Respirable manganese in ambient air due to MMT combustion would be many order of magnitude below the concentrations associated with occupational manganism and respiratory problems and also below those reported in isolated episodes of respiratory symptoms in communities near ferromanganese plants. Evidence was reviewed on the possibilities of: (1) increased absorption of inhaled manganese compared with ingested manganese; (2) hypersusceptibility of infants and persons of advanced age; and (3) increased absorption associated with iron deficiency. While relevant to high levels of exposure, these factors would not be expected to lead to toxic effects from the very low concentrations of Mn resulting from MMT use. Experimental animals that inhaled the combustion products of MMT in concentrations of approximately 10, 100, and 1000 micrograms Mn/m3 for 9 mo did not show toxic effects, although there was temporary elevation of tissue levels of Mn. Rhesus monkeys, susceptible to the neurologic effects of Mn, showed no symptoms after inhaling the combustion products of MMT in concentrations of 100 micrograms Mn/m3 for up to 66 wk. Monkeys exposed to 5000 microgram Mn/m3 also showed no symptoms. There is thus a wide margin of safety between the intakes of Mn essential to health and the high concentrations that have been associated with toxic effects. The small amounts of manganese added to the environment by the combustion of MMT used as a fuel additive would be comparable to the normal background and should not create health problems.

1. The relative effectiveness of a number of growth substances, both indole and naphthalene derivatives, in delaying leaf abscission in Coleus was tested by two methods of applying the compounds: by aqueous sprays and by lanolin mixtures applied by hand to cut petiole surfaces. 2. In the case of the spray applications the maximum effectiveness in delaying abscission was reached at approximately 0.05 per cent concentration of all compounds, with the exception of indoleacetic acid, which showed still greater effect at 0.1 per cent concentration. In most instances with the lanolin applications 0.05 per cent also represented the approximate maximum effective concentration. 3. The relative order of effectiveness of the various compounds differed considerably in the two methods of application. At the maximum effective concentration methyl indolebutyrate was the most effective in lanolin applications on petiole stubs, whereas in the spray application method β-naphthoxyacetic acid proved most effective. 4. With a...

The occurrence of several outbreaks of illness among workers handling castor bean pomace at eastern seaports in 1958 and 1959 led to an investigation of the toxicity of a number of commercial preparations. The conventional hemagglutination test and a toxic assay were used to study 14 commercial samples. The agglutination activity may be destroyed by heat without complete destruction of the toxic activity. Four of the samples collected were as toxic as the ricin sample used as the bioassay standard. In view of the potency of the toxin, ricin, and the failure of the agglutinating activity to correlate with the toxic properties of the samples, it is recommended that a toxin assay such as described in this paper be used to evaluate commercial preparations.

This report is based on an analysis of deaths in 4519 battery plant workers and 2300 lead production or smelter workers during the years 1947 to 1980. Causes were coded to the seventh (1955) revision of the International Classification of Diseases. There were significant excess deaths for "other hypertensive disease" (444-447) and "chronic nephritis" (592-594) in both cohorts, the standardized mortality ratios (SMRs) being 320 and 475, respectively, for the former causes and 222 and 265 for the latter. Proportionate mortality analysis, which adjusted for race, also showed elevated ratios, 241 and 388 for the former causes and 296 and 186 for the latter. Deaths from other hypertension-related diseases did not show comparable excesses. Renal cancer deaths were fewer than expected, SMRs being 41 and 74, respectively.

A population of 10,173 men, employed in 37 plants, was identified as having worked for at least one year in jobs involving probable exposure to vinyl chloride monomer (VCM) prior to January 1, 1973. Of the 9677 men whose vital status was determined, 707 were known to have died. For 699, death certificates were obtained. The standardized mortality ratio (SMR) for all causes was 89, that for all malignancies was 104. The only type of malignancy found in significant excess was in the category of malignant neoplasms of the brain and other parts of the nervous system; 12 deaths occurred where 5.9 were expected, for an adjusted SMR of 203. There were slight but inconclusive upward trends in all malignancies, and for malignancies of the respiratory tract, digestive tract, and central nervous system associated with reported levels of maximum exposure to VCM. When groups in whom less than 20 years had elapsed from the first exposure were compared with those with 20 or more elapsed years, and 25 or more elapsed years, no significantly different SMR's were detected for major primary sites of malignancy. Plans for an updated study of mortality, to include deaths in the period 1973-1979 are briefly discussed.

Classically, an intimate association has been recognized between nutritional deprivation and infection (1,2). The studies to be summarized in this brief presentation represent extensive investigations that have been carried out over the past 4 years at the University of Minnesota as we have begun to analyse under carefully controlled conditions in the laboratory, the relation of protein, caloric and specific amino acid deprivation and immune responses (3–6). For us these investigations, however, had their point of departure in clinical and field observations which suggested that different forms and different degrees of nutritional deprivation might have a profound influence on the development and expression of immunity. In 1968 one of us (R.A.G.) visited a former student and collegue Galal Aref who was working with refugie children in Egypt. Aref had found that when profound nutritional deprivation began in the neonatal period and was extreme it led to advanced protein deficiency and even Kwashiorkor already by 6 or 7 months of age.

SummaryAureomycin, although not a causative prophylactic against the Chesson strain of P. vivax, delayed the appearance of malaria in volunteers for at least 2 weeks as compared with controls. When given therapeutically in high dosage, the antibiotic had a delayed action against erythrocytic parasites, too slow to be of practical value. Infections were not cured.