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A variable energy neutral beam source is presented which utilizes a class of large molecules having the property of forming long−lived temporary negative ions. Negative ions are produced, accelerated, and focused, after which autodetachment of the electrons occur, leaving a beam of neutral molecules. The source has been used in total cross section experiments, where SF6 was the beam gas and various target gases were used in a scattering cell. Some results of the collision process SF6 + CO2 are presented. At 1200 eV lab energy (27 eV c.m. energy) the total collision cross section for CO2 is 54.2±15.9 A2. Advantages and disadvantages of this type of source are discussed, and extensions to other types of experiments are explored.

Three different laboratories independently investigated the ability of ingested mineral fibers to penetrate tissues in rats. All concluded that there was no evidence of tissue penetration by ingested mineral fibers. These experimental observations are supported by the findings in coal and hard-rock miners who swallow, during their lifetime, nearly 100 times the amount of dust that is stored in their lungs. The intestinal wall or mesenteric lymph nodes of these people show no evidence of storage of the ingested dust particles. Animals fed asbestos over much of their lifetime and allowed to live to the age of cancer production, failed to provide evidence of a cancerogenic effect.

A study was undertaken in the dog to determine whether changes occurred in the lymphatics of the endocardium and myocardium of both ventricles after obstruction of the cardiac lymphatics. Other investigators have reported ventricular subendocardial hemorrhage, increased elastic and fibrous tissue in the left ventricle endocardium, and opacification of the mitral valve leaflets. In 14 experiments the ventricular walls were injected with India ink. The efferent cardiac lymphatics were followed to their termination in the cardiac lymph node or nodes. These nodes were excised, as were afferent and efferent lymphatic trunks. After 4 to 16 weeks, with the aid of extracorporeal circulation and oxygenation, biopsies were taken of the myocardium and endocardium of the ventricles of the beating heart. Six animals were used as control subjects. Grossly, there were no changes in the endocardium, myocardium, or valve leaflets. Light and electron microscopy demonstrated no fibrosis or elastosis, and no lymphatics were identifiable. We were unable to establish evidence of permanent changes as a result of obstruction of the lymphatics of the dog heart.

The following reaction variables were studied and reported on: Temperature, stirring rate, nature of the organic solvent and concentration of the reactants Amine solubility is important in determining polymer yield. Der Einflus folgender Reaktionsvariabler wurde untersucht: Temperatur, Ruhrgeschwindigkeit, Art des organischen Losungsmittels und Konzentration der Reaktanten. Die Ausbeute an Polymeren wird wesentlich durch die Loslichkeit der Aminkomponente mitbestimmt.

The rationale for the use of prophylactic antibiotics in clean orthopaedic surgery was explored by means of an experimental model suited to the investigation of (1) antibiotic penetration and persistence in operative hematomas in bone and (2) the effect of cephaloridine administration on standard wound infections. Cephaloridine was found to penetrate hematomas in bone readily and to persist there in bacteriocidal concentrations. When cephaloridine was given preoperatively, all wounds were converted to bacteriological sterility and did not become clinically infected. When cephaloridine was begun six hours or later after contamination, infection occurred uniformly.

(1936). Bibliography of Health and Physical Education. Research Quarterly. American Physical Education Association: Vol. 7, No. 4, pp. 3-43.

“Because simultaneous attention to words and music allows the music to organize the text and reveal the point which its words are being used to make, we are proposing that what we call a hymn is the resultant meaning of the sounds-as-words and the sounds-as-music. The musical-verbal phenomenon that performs a function in the church's worship is not the verbal meaning and the musical structure as two parallel or added quantities. It is the meaning that results from the fact that the same sounds articulate both; both are heard simultaneously, and the one reveals the meaning of the other.”

A need for more reliable tests for speed of reading has been felt both in researches concerning legibility of type and studies of improvement of reading ability. This article reports two steps in the development of tests for measuring reading speed of material of the fourth grade level. The first step was the drawing of ideal specifi cations and the preparation of the content. The second step was ad ministration of tests to approximately 3,000 persons, and the calcula tion of age and grade norms, of practice effect, of absolute zero, and of individual and group variability.

ALTHOUGH pain as a syndrome may be said to have existed since the world began, in contrast to other sensations it can be defined as a sensation of exception, or scientifically speaking, one of pathology. It is true that the pain syndrome possesses certain educational properties and appears as such especially in childhood and infancy when the movements and the life of adaptation begin. Notwithstanding this fact, however, pain in itself does not enter into the realm of those functions which are said to be absolutely necessary for normal life. We all know that normal adult life may be free from pain for a long period of time; this in itself can serve as an argument for the necessity of the existence of such sensation as pain. In some instances unquestionably the duty of pain is to signal to our conscience the existence of some stimulus which is damaging to the organism, and its purpose is to induce, even before conscious sensation, those immediate defensive reflex mechanisms which are at the disposal of the ...

In this paper we derive the expression for force on a magnetic dipole in an elementary way but without using “poles.” The equation F = (μ ·∇)B follows from concepts of electromagnetism already familiar to the first-year student. This is accomplished by working with forces on current elements and grouping terms to attain recognizable vector identities. In a similar manner, it is shown that the potential energy is U = −(μ·B). Introductory physics texts generally do not discuss force on dipoles. More advanced texts treat the problem by analogy to the electric dipole or by pure mathematical formalism which is beyond the level of the beginning physics major.

Adsorption of clay particles from very dilute aqueous suspensions onto positively charged films (Cytochrome C) on carbon coated support grids has been used to obtain well dispersed samples of the particles suitable for detailed electron microscopic examination. The natural negative charge of the carbon coated grid was used for ferric polycations and precipitates.

The prognosis in tuberculosis of the larynx has decidedly improved since Sir Morrell Mackenzie 1 in 1880 made the statement so often quoted that "the prognosis of laryngeal tuberculosis is always extremely unfavorable and it is not certain that any cases ever recover." Search of the French and German literature of that era revealed the prognosis to be equally hopeless. Sir St. Clair Thomson 2 in 1924 said: "A Group I patient (that is a slight case) with a laryngeal lesion has a worse prospect than a Group II case with a sound larynx. And a Group II case (that is a severe case) with throat trouble has a gloomier expectation than if he had a healthy larynx, but lungs so involved as to be classed in Group III (that is an 'advanced' case). Differently expressed, the discovery of a laryngeal lesion at once moves a case down to a lower group."

T HE importance of a person's vocabulary has been emphasized by a number of investigators, both in fields of general mental ability and in vocational success. Most of these investigators used general-vocabulary tests which, on inspection, are found to contain few technical words. The tests do contain many words chosen from literature which have little significance in either scientific or commercial fields. Moreover, some of the words chosen are difficult simply because of their rareness, not because of the intrinsic complexity of thoughts expressed. A fairly large number of tests of achievement in special subjects have included lists of technical terms, but none have appeared which systematically sample basic vocabularies in important subject-matter fields, in a reasonably short time, say two hours. A vocabulary profile for the superior adult is desired which will indicate the range of his concepts in fields which are important and independent, and allow more adequate solutions of