Ordinary View Research Articles

Penetration of retinal and vitreous opacities in diabetic retinopathy. Use of infrared fundus photography.

Infrared radiation has the capability of penetrating some types of opacities so that photographs can be made with infrared sensitive film of structures that cannot be seen by the human visual system. This technique was applied to ocular fundus photography in patients with various manifestations of diabetic retinopathy including retinal hemorrhages and exudates, neovascular tufts, marked proliferative tissue, and vitreous hemorrhage. In all such cases the infrared photographs depicted the optic disc, retinal vessels, and choroidal vasculature underlying the opacities when these structures could not be seen through the intervening opacities in routine photographs or on clinical examination. This technique has potential for revealing fundus abnormalities hidden from ordinary view by retinal or vitreous opacities.

Generalization of Einstein's Principle of Equivalence so as to Embrace the Field Equations of Gravitation

It is shown that the apparent impossibility of deriving Einstein's field equations of gravitation in a way similar to that used by him in deriving the equations of particle motion and electromagnetism–being a direct generalization of his famous imaginary experiment of a box falling freely in a gravitational field–may be overcome by using the quantal vacuum with its fluctuations instead of the vacuum of ordinary physics with its absolute emptiness. Thus, the Dirac equation with gravitation, thereby used, appears, in contrast to the ordinary view, as the prototype of interaction theory based on general principles, one of them being a generalized principle of equivalence.

Herodotus and the Strategy and Tactics of the Invasion of Xerxes

IN the nineteenth and twentieth centuries Herodotus has received perhaps more than his fair share of attention from classical scholars. A number of very good books have been written on him, as well as other studies on his subject matter, the Persian Wars.' In addition, the scholarly journals contain so many excellent articles dealing with Herodotus that the present-day student can digest them only with considerable effort.2 Yet in recent years the veritable spate of books and articles on him has continued to appear.3 In one major area, however-Herodotus' understanding of strategy and tactics-there has been very little work. Nineteenthand twentieth-century historians of the Persian Wars have been so concerned with the problem of reconstructing their strategy and tactics along lines suitable to modern military academies that they have devoted little attention to the simple question: how well did Herodotus understand the principles of strategy and tactics ? Actually, he did comprehend the strategic and tactical problems of the Persian iinvasion, a comprehension he displays in many passages. At other times, however, a number of weaknesses appear in his narrative of military events; these weaknesses have too often caused scholars to overlook the perceptiveness of his account, but, as we shall see below, they illuminate a major aspect of his historical thought. This is not the ordinary view of most historians of the Persian Wars, who maintain that Herodotus had little or no knowledge of strategy and tactics. R. M. Macan, G. B. Grundy, Amedee Hauvette, W. W. How and

An analysis of linguistic signs occurring in suppositio materialis or the meaning of quotation marks and their phonetic equivalents

In this paper I propose to discuss the time-honoured problem of linguistic signs occurring in suppositio materialis, a problem which has recently been given some attention. The problem may be stated as follows: What is the subject in a sentence like “Happily was spelt incorrectly”? And to what word-class does it belong? I shall show that the ordinary view of the suppositio materialis employment of signs — that e.g. ‘happily’ is a noun in this employment — is seriously fallacious. The notions of subject and subject of discourse have not been kept distinct. (The subject ( = grammatical subject) in ‘Anderson smokes cigars’ is ‘Anderson’, whereas the subject of discourse is Anderson) In other words, signs and what signs are signs for have not been kept distinct. This is a mistake the linguist often accuses the layman of committing. But unfortunately he often commits it himself. In connexion with my analysis I shall call attention to an important distinctive feature of the language (metalanguage) the linguist uses in describing languages.

The Place of Science in our View of History

ON several occasions the pages of NATURE have afforded evidence of the growing importance taken by science in the writing and teaching of history. It is, in fact, at the root of the difficulty which was dealt with recently in one of the leading articles. How to secure that our political leaders—and one might well add leaders of all other kinds—should approach their business in a scientific spirit? There are, of course, many ways by which the change will come, and is coming, but it may be doubted whether any way will affect a larger number of persons than that of infusing the ordinary teaching and view of history with some notion of the part that science has played in the process. For we all learn some history. Not only at school but also in after life, so far as we do any serious reading at all, it is of a historical kind; floods of memoirs and biographies are being constantly poured out by the press. The History of British Civilization. By Dr. Esme Wingfield-Stratford. Vol. 1. Pp. xv + 574. Vol.2. Pp. viii + 575–1332. (London: George Routledge and Sons, Ltd.; New York: Harcourt, Brace and Co., Inc., 1928.) 42s. net.

The Drift of Meteor Trails

IN the Astronomical Column of NATURE of May 23 there appears a note on the currents in the upper air as revealed by the direction of drift of the streaks left by meteors. Before we can say with certainty, however, that such drift represents movement of the air, we require to know the real nature of a meteor trail. The ordinary view seems to be that the trail is composed of air heated by the meteor in its flight through the atmosphere, the heating being produced not so much by friction as by the compression of the air in front of the meteor. But is it physically possible for a mass of air so heated to retain its heat so as to remain luminous for any length of time? Streaks have been seen which remained luminous for more than two hours, and though this is exceptional, yet any explanation which would account for long-enduring trails would apply also to the more transient kinds. Is it not possible that the trail is an electrical phenomenon akin to an auroral streamer, or to the patches of light seen during an aurora? The movement of both trails and streamers is usually towards the east, but both more rarely move in other directions. The movement in the case of the aurora is presumably due to the passage of electrified particles moving in the earth's magnetic field, and deflected by it. Is it possible that a meteor trail is due to the passage of electricity through rarefied air that may have been ionised by the passage of the meteor?

Vedic, Sanskrit, and Prakrit

It will be the object of this paper to point out some difficulties in the ordinary view of the relation of the Vedic and Classical Sanskrit to the popular or Prakrit dialects, and, if possible, to suggest another theory which will avoid these difficulties. And in making this attempt, instead of starting with a discussion of What is Sanskrit?, a procedure which seems to have led to no definite result', I shall begin with the consideration of the question as to what is Mittelindisch or JPrakrit 2, hoping that if a satisfactory solution of this question is reached, the problem of the origin of Sanskrit will be materially simplified. The normal view of the relation of Prakrit and Pali to the Vedic and Sanskrit is that suggested by the word Mittelindisch itself, namely that Prakrit is the direct lineal descendant of Altindisch or the language of the oldest stage of the transmissions. And since this oldest stage is found in two distinct forms,. namely the Vedic and Classical Sanskrit, the inference is that Prakrit is derived either from the Vedic language 4 or the Classical, or at least from popular languages to which the Vedic or Classical Sanskrit was related like all literary lan-

VIII.—On Plagioclinal Mountains

The object of this paper is to show that the received explanations of the structure of mountain chains will not account for the formation of certain Precambrian ranges, and to state facts in support of a new theory of the origin of some mountains. A brief summary of the ordinary views of the subject will first be necessary.

IV. On a new arrangement of binocular spectrum-microscope

The spectrum-microscope, as usually made, possesses several disadvantages: it is only adapted for one eye; the prisms having to be introduced over the eyepiece renders it necessary to remove the eye from the instrument, and alter the adjustment, before passing from the ordinary view of an object to that of its spectrum, and vice versâ ; the field of view is limited, and the dispersion comparatively small. I have devised, and for some time past have been working with, an instrument in which the above objections are obviated, although at the same time certain minor advantages possessed by the ordinary instrument, such as convenience of examining the light reflected from an object, and comparing its spectrum with a standard spectrum, are not so readily associated with the present form of arrangement.