acid gas, 22; crypton, 41; and xenon, 64. With such differences in density, it is evident that the gases are not present in equal proportions. With the knowledge of the properties of the different gases, of their weight and their liquefaction temperature, we may determine approximately what the proportion should be at different altitudes. In the high regions of our atmosphere hydrogen, accompanied by a little helium, reigns supreme, while the heavy gases which constitute the atmosphere in which we live and breathe exist only on the surface of the earth. Color of the Sky

The commonly accepted theory that the blue color of the sky is due to the refraction of light caused by solid or liquid particles floating in the air was disputed by the American physicist, Professor Spring, who declared that in his laboratory experiments he had never succeeded in obtaining a blue color, the reflected rays of light always showing either red, yellow or violet. Purification in no case removed the blue tint from the air. After exhausting all physical means in an attempt to reproduce the blue color, Professor Spring concluded that the blue of the sky depends upon chemical conditions and that the color deepens as the observer rises above the earth.

Report of the Meteorological Committee

The International Meteorological Committee, appointed to investigate the general circulation of the atmosphere, published its conclusions in a report drawn up by the chairman of the committee, H. Hildebrandsson, the celebrated meteorologist of Upsal. The conclusions, all drawn from actual experiments were briefly stated as follows:

(1) Above the equator-more exactly above the thermic equator and the equatorial calms there is present during the entire year an eastern current, with an average speed of thirty-seven metres per second. (2) Above the region of the trade winds there reigns an upper contra-trade wind current from the southwest in the boreal hemisphere and from the northwest in the austral hemisphere.

(3) This contra-trade wind current deviates more and more to the right, and becomes a western current above the crest of the barometric maximum of the tropics, at which point it descends to feed the trade winds.

(4) The regions situated at the equatorial limit of the trade winds sometimes into the trade winds, some

enter

according to seasons

times into the equatorial calms. Above them there is consequently an upper monsoon, the contra-trade wind in winter and the equatorial current of the east in summer.

(5) From the high pressure of the tropics the average pressure of the air diminishes continually toward the poles, at least into the neighborhood of the polar circle. Further, the air of the temperate zones is drawn into a vast polar whirlpool turning from the west toward the

east.

(6) The sheets of the upper air of the temperate zones extend above the high pressure of the tropics and descend there.

(7) The irregularities which are found at the surface of the earth, particularly in the regions of the monsoons of Asia, disappear, in general at the height of the lower or intermediate clouds.

(8) We must entirely abandon the idea of a vertical circulation between the tropics and the poles, which has been believed up to the present in accordance with the statements of Ferrel and Thompson.

New Views of Matter

Considerable scientific interest was aroused by the address of Sir William Crookes before the International Chemical Congress in Berlin, in which he dealt with the possibility of reducing all the elements of matter to one, and ultimately finding this resolvable into a single form of energy. Speaking of the significance of the Roentgen and Becquerel discoveries and those of the Curies and others, he said: "All these observations find internal connection in the discovery of radium, which is probably the basis of the coarser chemical element. Probably masses of molecules dissolve themselves into the ether waves of the universe, or into electrical energy. Thus we stand on the border line where matter and force pass into each other. In this borderland lie the greatest scientific problems of the future. Here lie the final realities, wide reaching and marvelous."

The theory advanced by Sir William Crookes was in line with the discovery announced shortly before by Professor Stephen M. Babcock, of the University of Wisconsin, that the weight of an atom is inversely proportional to its inherent energy. Simply stated his theory is that

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all atoms are the same, but endowed with varying kinds and qualities of energy, which give the atoms their varying forms. The theory advanced at Berlin, however, goes a step farther, supposing a possible disintegration of matter. "It is possible," concluded Sir William Crookes, "that formless nebula will again prevail when the hour-glass of eternity has run out."

Discovery of Polonium

Another important announcement made at the Berlin Chemical Congress was the discovery of polonium, a new elementary substance, by Professor and Madame Curie, of Paris. The properties of the new elements were too little understood to determine the future usefulness of polonium, but scientists were inclined to the belief that it might be found to perform the functions of the so-called X-Rays far more powerfully, and without the somewhat cumbrous apparatus essential to their use. In a higher degree than radium, it possessed the property of shining in the dark, and although it was shown that actual particles were being shot out from it continually, this strange substance did not seem to exhaust itself nor to lose its luminous power.

Radium and Radio-Activity

Sir William Ramsay, Professor of Chemistry at University College, London, in a lecture before that institution, made the announcement that his experiments with radium had shown that that element had the power of changing by some subtle process into another element, namely, helium. He described how a long search into the problem of what becomes of the minute particles with which radium is always parting was eventually rewarded. Besides its other manifestations, he found that radium constantly gives off an emanation which behaves in all respects like a heavy gas. It could be collected in tiny flasks, measured, weighed, and used to display the characteristics of radium, but it was not permanent. In about a month it entirely disappeared. Catching this emanation in the act of vanishing Sir William Ramsay found that after it had been collected a couple of days its spectrum began to display the typical yellow line of helium; that in four or five days the helium lines grew brighter, and that in a week the spectrum of helium was blazing in the hermetically sealed tubes that had been filled with the