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A rapid, precise method for the determination of uranium in nitric acid solution is presented. The uranium in solution is excited by a primary x-ray beam from a molybdenum tube. The intensity of the uranium La, emission line is measured by means of a crystal spectrometer employing a scintillation counter and pulse height analyzer. This intensity is converted to concentration by relating to standard solutions The modification of commercial equipment that simplified the solution analysis are described, as are comparisons of various instrument components.

Submilligram quantities of boron were completely extracted from aqueous solution into methyl isobutyl ketone as the tetrabutylammonium boron -- tetrafluoride ion association complex. The boron content of the separated organic phase was determined by direct flame spectrophotometric analysis, using an oxygen-sheathed oxyhydrogen flame as the excitation source. Of 30 metal ions studied, only five interfered at a l to 1 mole ratio to boron. Interfering anions were phosphate, perchlorate, and high levels of nitrate. Nitrate interference was eliminated by suifuric acid fuming prior to extraction. (auth)

The Salmon event was a 5.3±0.5 kt nuclear detonation at a depth of 827.8 m in the Tatum salt dome in Mississippi. The explosion created a nearly spherical cavity of radius 17.4 ± 0.6 m and vaporized and melted approximately 5.4×106 kg of rock which formed a puddle of recrystallized salt. At the time of penetration the cavity was under a partial vacuum with a pressure of less than. 313 mb, and the temperature of its gases was about 205°C. Most of the explosion energy was in the form of heat distributed within 45 m of the shot point. Radioactive melt injected into cracks was observed as far as 37 m from the shot point, and radioactivity increased above background as far as 64 m. The wall rock was highly microfractured and contained some macrofractures. The most broken portion of the rock surrounding the cavity was observed in the region 39 to 50 m below shot point. The puddle at the base of the cavity was highly fractionated, with a high concentration of refractory radioactive species in the bottom few centimeters. Separation of Xe131 in the cavity gas from the parent I131 found in the puddle indicates that the puddle took 24 to 32 days to solidify. It is concluded that the resulting cavity is stable and could be used for an experimental investigation of full or partial decoupling; however, the material surrounding the cavity is less competent than it was before the shot, and the present strength and stress distribution of the rock are not known.

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Beryllium is determined spectrographically on air sample filter papers by direct sparking of the filter paper mounted on a silver disk which revolves on a rotating platform electrode apparatus eccentric from a silver counter electrode. The procedure is fast and precise, with a minimum of sample handling and can be used with samples containing as little as one mμg of beryllium

A spectrographic method was developed for the complete cation analysis of high-purity water by spark excitation of the evaporated sample on pairs of silver electrodes. The procedure is fast and precise, with a minimum of sample handling and adequate sensitivity for determining verv small amounts of trace impurities. (auth)

Gaseous Combustion at High Pressures: being mainly an Account of the Researches carried out in the High Pressure Gas Research Laboratories of the Imperial College of Science and Technology, London, together with the Equipment and Experimental Methods Employed

Continuous monitoring of hydrogen in flowing nitrogen gas was needed in connection with experimental work at the USAEC's National Reactor Testing Station. One of the methods investigated was emission spectroscopy, using quartz envelope electrodeless discharge tube excitation. The sample gas was passed through a cold trap to eliminate water vapor and hydrocarbon vapors before entering the discharge tube at a pressure of two mm Hg. Using a grating monochromator with photomultiplier detection set at 4861.3A hydrogen can be determined down to about 0.05% (v/v).

Demountable hollow-cathode lamps have frequent application as sample emission sources in high resolution spectroscopy1,2 and as light emission sources in atomic absorption spectrometry.3,4 We are interested in both of these uses and also the application of the lamps for the sample absorption sources in atomic absorption spectrometry.

IN NATURE of Dec. 11, 1926, p. 837, Prof. W. A. Bone stated that he would at some future date publish the results of experiments on the uniform movement of flame which disproved the law of speeds. The work referred to has now been published in the Proceedings of the Royal Society (A, 114, 420; 1927) and we can reply to Prof. Bone's letter. The principal mixtures he has chosen to test the law of speeds are of ethylene and acetylene with oxygen, and the choice is made because, to use Prof. Bone's own expression, these mixtures are so sensitive (i.e. highly responsive to accidental changes in experimental conditions).

MR. A. G. WHITE, in his letter in NATURE of Jan. 8, p. 51, correctly recalls the fact, which we discussed fully in our original publications in theJournal of the Chemical Society, that deviations from the law of speeds may be expected if one of the combustible gases in a complex mixture interferes with the burning of another. The deviations are, however, small and their nature can be predicted.

IN the year 19311 Prof. W. A. Bone and Mr. R. P. Fraser published figures for the speed of the uniform movement of flame in moist (stated to be saturated at 12°–13°) mixtures of carbon monoxide and oxygen. Their values are represented by the crosses in the accompanying diagram (Fig. 1). In a paper published in 19322, we challenged both the absolute and the relative correctness of those values. Our results, for mixtures saturated at 13.1°, are indicated by circles in the diagram. Prof. Bone and Mr. J. Bell have repeated the experiments3 and, whilst unable to confirm the earlier determinations, have obtained some (for mixtures saturated at 15°) that correspond with ours, within the limits of reasonable experimental error, as is shown by their curve reproduced in the diagram.

IN 19321 we found that the mixture of carbonic oxide and oxygen which gave the maximum speed of flame during the uniform movement was approximately that for combining proportions (2CO + O2), in accordance with the theory advanced earlier2. This conclusion is supported by recent experiments carried out at the U.S. Bureau of Standards by Fiock and Roeder3, using two different methods for measuring the speed of flame, with central ignition (a) in a closed sphere and (b) in a soap bubble. The concentration of moisture was carefully measured and kept constant in each series (a necessary precaution which we emphasised in our paper), but differed in the two series, being 2·7 and 3·3 per cent.

IN view of the publication by Fischer (Brenn. Chem., 9, 309; 1928) of the results of his experiments on the thermal decomposition of methane, to which reference is made by Messrs. Stanley and Nash in a letter published in NATURE of Nov. 10, it seems desirable to place on record the fact that the production of commercial yields of benzene by the pyrolysis of methane, without a catalyst, was proved in the Fuel Technology laboratories of the University of Sheffield about two years ago. The work forms the basis of certain claims in Engiish Patent No. 26719 of Oct. 8, 1927.

FROM TIME TO TIME, I have mouthed the platitude that the nursing profession as a whole is interested in changing many aspects of the current nursing situation. However, a number of villains variously cast as the public, patients, hospital administrators, or doctors oppose these legitimate aspirations. But the facts of the case are these: Most nurses are not overly concerned with the many problems and proposed changes which are frequently advanced by the leaders of our profession. Our problem in nursing is not with persuading outside groups as much as it is in persuading the majority of nurses of the need for various reforms in nursing. As has been said so often, "We are our own worst enemies." For instance, much heat and some light are being shed on the needs of nursing service as they must affect changing patterns in basic nursing education. And today there are a wide variety of educational pathways by which a young person may enter a career in nursing. Although these pathways are somewhat familiar to all nurses, their purposes and objectives are poorly understood by many of us. Our rapid proliferation of various nursing curriculums for the beginning nursing practitioner reflects the nation's need for a larger supply of nurses with more than one type of preparation. Unfortunately, this movement has provided a battleground for nurses, and we have joined one or another armed camp, depending on our educational preparation and nursing interest area. This failure of nurses to accept and to encourage curricular experimentation among the schools of nursing in this country has been a major reason for some of our present professional difficulties. While it is not unusual for groups of nurses to disagree with each other, it is unusual for nurses to be forthright and honest in identifying the issues, in meeting face-to-face to find workable solutions to these is