268 



NATURE 



[May 25, 1916 



broadest meaning', lays stress on the evil arising from 

 the ever-increasing specialisation amongst chemists, 

 and emphasises the present waste of effort involved in 

 the publication of so many overlapping journals. Mr. 

 C. T. Kingzett, in an article in the Chemical Trade 

 Journal for April 8, develops the same theme. He 

 advocates the establishment of a "real" Institute of 

 Chemistry, to comprise the present Institute, the 

 Chemical Society, Society of Chemical Industry, etc. 

 He also indicates the waste of time, energy, and 

 money involved in the present independent status of 

 the various chemical associations, and remarks on the 

 narrowing influence resulting from the lack of mutual 

 association between them. 



The April part of Science Progress contains several 

 articles of interest. Sir Ronald Ross contributes a 

 further instalment of his researches into the theory 

 of equations; Dr. Johnstone, under the slightly mis- 

 leading title, "The Mathematical Theory of Organic 

 Variability," provides an elementary account of the 

 genesis of Prof. Pearson's family of frequency curves; 

 and Mr. C. Mansell Moullin discusses the natural 

 history of tumours. Other contributors are Prof. 

 Fraser Harris and Mr. Joseph Offord. A valuable 

 feature is a sketch of recent progress in various de- 

 partments of science under the heading. " Recent 

 Advances in Science." Few readers will dispute the 

 justice of the bitter strictures which bulk largely in 

 the editorial notes upon our. national neglect of 

 science. 



OUR ASTRONOMICAL COLUMN. 



Comet or Nebulous Minor Planet? — At the 

 Konigstuhl Observatory a photograph taken on 

 April 3 showed what seemed to be a new 

 minor planet, which received the designation 

 1916 ZK. Its daily motion was — o-6m. and 

 + 3', whilst its magnitude was 130 (Astronomische 

 Nachrichten, 4841). Three days later, on another 

 photograph, it presented a nebulous appearance. This 

 was more strongly developed by April 27 {Astro- 

 nomische Nachrichten, 4843). Dr. Max Wolf's obser- 

 vations have been confirmed at the Babelsberg Ob- 

 versatory (Astronomische Nachrichten, 4843). On 

 April 30 the nebulosit}^ involved a stellar nucleus. 

 This remarkable body evidently bears a likeness to 

 Neujmin's comet 1913c, which resembled a minor 

 planet when first discovered, but a few days later 

 developed a weak cometic chevelure ; and the latest 

 observations indicate that it is really a new comet. 

 The position of the object on discovery was : — April 3, 

 R.A. i2h. 52-9m., declination +0° 11'; on April 30, 

 I2h. 58-9m., +2° 39-6'. The daily motion on April 27 

 was — o-5m. and +5' and the magnitude was 13-3. 



The Pole Effect in the Calcium Arc. — Important 

 quantitative details concerning the pole effect in the 

 arc spectrum of calcium (AA 3000-4200) are given by 

 Messrs. Gale and Whitney in the Astrophysical Journal 

 (vol. xliii.. No. 2). The measures of spectra from a 

 horizontal arc 4 mm. long, carrying 4 amperes on a 

 iio-volt circuit, with calcium electrodes 7 to 10 mm. 

 in diameter, indicate a progressive change of from 

 o-oi to 0-02 tenth metres between positive and nega- 

 tive pole correlated with the series classification of 

 the lines. Although the pole effect seems to be in- 

 dependent of the vapour density of the radiating ions, 

 negativing the suggestion that it is due to the in- 

 ternal pressure of the arc, yet it shows a parallel 

 relationship with the pressure shift. Very significant 

 is the reversal of the gradients of both intensity 

 and pole effect observed when the current is reversed 

 In an arc having one pole of silver, the other being 



NO. 2430, VOL. qy"] 



of calcium. The authors suggest that the pole effect 

 depends on the amplitude of vibration of the elec- 

 trons. 



The Rotation of Nebul.«. — Some additional data 

 concerning rotating nebulae have been obtained at the 

 Lick Observatory by W. W. Campbell and J. H. 

 Moore (Bulletin No. 278). In spectrograms of the 

 complicated planetary nebula in Aquarius, N.G.C. 

 7009, taken with the slit set on the major axis of the 

 image, the maximum displacements of the two chief 

 nebular lines indicate a rotational velocity of 6 kilo- 

 metres per second at a distance of 9 seconds of arc 

 from the nucleus ; the inclination of the lines gave 

 a similar result. In the case of N.G.C. 6543, the 

 historic planetary in Draco, the central por- 

 tion of the nebula, about 6-7* diameter, is rotating 

 about an axis in P. A. 130°, with a velocity of 

 c km. /sec. In both cases the nebular lines, in addi- 

 tion to the general inclination, are also somewhat 

 contorted, indicating lower velocities in the outer re- 

 gions. These observations lead to some very interest- 

 ing conclusions regarding the probable masses of the 

 nebulae. Corresponding to an inferior limit of dis- 

 tance of 100 light-years, their respective masses would 

 be 11-3 and 28 times solar, whilst the mean density 

 of N.G.C. 7009 would be of the order of ixio"® times 

 that of hydrogen at 0° C. and i mm. of mercury. 

 The density of N.G.C. 6543 appears to be about five 

 times as great. It Is considered that the evidence 

 indicates that planetary nebulae must be regarded as 

 three-dimensional objects. In this connection it was 

 suggested many years ago that a bright ellipsoidal 

 shell viewed from a distance would present the appear- 

 ance of a ring nebula. 



NATIONAL DEFENCE AND DEVELOP- 

 MENT IN THE UNITED STATES. 



THE proceedings of the American Association for 

 the Advancement of Science at its annual meet- 

 ing held at Columbus at the end of last year 

 were characterised by a large number of papers read 

 before the section devoted to Social and Economic 

 Science on various aspects of national defence and 

 development, a reprint of which appears to the num- 

 ber of eleven articles in the Scientific Monthly of New 

 York for the month of April. 



The events of the European war seem to have 

 awakened in the minds of the economists of the asso- 

 ciation dire anticipations of similar devastating results 

 to the United States so soon as the war is concluded, 

 and they have hastened to recommend the most extra- 

 ordinary provision and a vast expenditure in order to 

 place the nation in a condition of complete defence 

 by the establishment of a standing army of from 

 half a million to a million men, of a great reserve, 

 and of a navy at least equal to that of the greatest 

 European naval Power. The doctrine of "prepared- 

 ness " seems to have taken firm root amongst them, 

 together with the dictum quoted from Washington, 

 "To be prepared for war Is the most effective means 

 of promoting peace." The success of Germany in the 

 early days of the war, and the efficiency of her military 

 arrangements, have evidently made a deep Impression 

 on the American mind. It is pointed out, for example, 

 that England spent 535 years of the nineteenth century 

 in war, and France not much less, whilst Prussia 

 spent but thirteen years, the result of her extraordinary 

 preparedness. As a result of her efficiency, she 

 "quickly finished her fights and got back to work. 

 The wars of the other nations were long drawn out, 

 due, as we know, to the necessity of their learning 

 and preparing to fight after their wars had begun." 



It is claimed that a condition of perpetual and 



