3.^2 



NATURE 



[May i8, 191 i 



It U now clear that all liio»c agcnli* which inhibit 

 the ruhting of iron (see Journ, Chcra. Soc., 1905) alwj 

 rendtr the iron " passive " to a greater or Ie»» extent, 

 and tiiat this passivity of iron p(^r8il^^8 after the 

 metal has been removed from the effective solution. 

 Iron which has bf<;n immersed in alkalis or in a 

 solution of |K)tussium bichromate is found still to be 

 passive after careful wasljing with water, that is, after 

 removal of all trace of the solution which produced the 

 4flect. The iron is no longer attacked by nitric acid of a 

 certain strength or by the appropriate solution of copper 

 sulphate, nor does it " rust " in presence of oxygen and 

 water. Contact with certain substances, especially dilute 

 acids, including carbonic acid, at once destroys the 

 passivity, and the iron becomes active again in all respects. 

 A full account of this work and of its bearings will shortly 

 be given. 



Ihe fact alluded to in recent correspondence, that an 

 iron cylinder which has been immersed in potash solution 

 and afterwards washed with water will not rust in air 

 until carbon dioxide is admitted, does not prove that 

 carbon dioxide is necessary for rusting. The ob.served 

 facts are due, first, to the passivity of the iron induced by 

 the alkali, and, secondly, to the destruction of this 

 passivity by the carbon dioxide. The .same piece of iron 

 will rust freely in air deprived of carbon dioxide, provided 

 that it has not been in contact with alkali of such a 

 strength as will induce passivity. 



May 9. WvNDiiAM R. Dt nstan. 



SCIENCE AND THE IMPERIAL COS FK HENCE. 



SUCH words as Empire and Imperial, like manj 

 others, suffer some disadvantage from their his- 

 torical ani(C( (1. Ills. Looked at in the past they recall 

 scMnethin^ Roman. sDmethingf Napoleonic; the rule 

 of dependent peoples, conquered by the sword, and 

 governed, not wholly inefhciently, but without much 

 say in the matter, by military power. Looked at in 

 the present and with a scientific eye, the British 

 Empire reveals itself as something fundamentally 

 different. It is simply the last term of social aggre- 

 gation. Free peoples, starting from the family, aggre- 

 gate themselves into larger and larger groups, and 

 the common freedom is maintained by the nav'al 

 supremacy of the mother-country. The Crown conse- 

 ciates the unity of the whole. 



Every stage of aggregation in such a system has 

 its common interests which require concerted action. 

 The recognition of this inevitably leads to some sort 

 of what Herbert Spencer would have called physio- 

 loeic.i! intt'i^ration in which the whole is greater, or 

 at an\ rail more efficient, than the sum of its parts. 

 The Impniil ( "iMifiiince, which is about to meet, has 

 (■(inii' iiiio 1 \i-~iriu( iiist as naturally as a municipality 

 ur a ('cuiiii\ (imiuil. The essential principle i^ ilir 

 s iiur : ihc >C()|)i' (li its deliberation will onI\ iMmuI 

 ti> larger problems. 



-Such problems will be matters of hiijli [xilicv. and 

 thoutrh it may be hoped that they will be dealt with in 

 a scientific spirit, it is improbable that the direct 

 interests of knowledge will for the moment find a 

 place amongst them. Rut the principle of Imperial 

 Conference, which happily there is every reason to 

 regard as permanently established, has alreadv received 

 a development in a more detailed direction. The 

 Imperial Education Conference, which held its last 

 public sitting on .\pril 28. has now received Govern- 

 ment recognition, though its first meeting in iqoj was 

 the result of unofficial initiative. It is not improbable 

 that it-; (xainpli' mav he followed on behalf of other 

 inton^>!s (if 110 less inmortance. 



KnowU'diic in a logical order would como hefoii' 

 education. But the machinery of an Tmporial ronf«i- 

 ence would prohahlv not he verv !- ih • pv^^- 



NO. 2168. VOL. 86] 



gress of science in ih<- abstract, a* that .•■■-• > 



earmarked to any natic^nality. The scientiri' 



the Empire itself is a field in which ih -i 



could find employment with results of 



found scientihc interest and the :Jr' 



utility. 



Looking at the magnitude o I . ' 



is more remarkable than the feeble inlere>l it e\ 

 i'l the mind of the average citizen. His hori/- 

 rarely more than partjchial, and the only inip*:,.:! 

 problem on which he probably has a distinct convif - 

 lion is the necessity of maintaining our naval ^^ 

 macy. It is something that in a vague way ho ^'' 

 wish it to be maintained. But what the F" 

 or what are its future possibilities, he neit). 

 nor cares. In this he is hardly to be blannu. li' 

 was taught in his youth, as we may ie.irn from the 

 '■ Reminiscences of Goldwin Smith," that Colonies wer- 

 a source of weakness, and we may learn from th< 

 same authority that half a century ago even •' 

 Colonial Office was animated with the idea of g' 

 rid of them decently. If, since that day, opinion 

 changed to acquiescence in the existence of Er 

 it is due to the influence and advantages of a peat. :,.. 

 commerce. Perhaps in generations to come it ma\ 

 excite a livelier enthusiasm. 



A common attack, such as a conference i 

 stimulate, on scientific problems, might do som» 

 to bring this about. There is no suggestion thai 

 science should be centred in the home-country. The 

 dominions have their own scientific activity, and fn»- 

 ranks of the Royal Society are open to their workers. 

 The problems that demand cooperation are not local 

 but far extending, even cosmiral. 



Our .Admiralty has charted ' ' res frequented 

 b/ our shipping, and the woi ^sition has the 



benefit. The international recoj^niiion of the meridian 

 of Greenwich is our reward. But though the Chal- 

 Icnt^cr expedition made a noble beginning, a thorougli 

 exploration of ocean depths still remains to be accom- 

 plished, and is a task which naturally falls to ;t 

 maritime race. But the land cries out to be accurately 

 mapped. Both .Africa and .Australia have suffered 

 from using imperfectly determined meridians of longi- 

 tude as boundaries. The accurate determination ot 

 the position of salient points throughout the Empin 

 would alone be a sufficient subject for a conference 

 Were this accomplished local surveys would start from 

 a sound basis in filling up the details. .As it is, even 

 the survey of the United Kingdom is not absolute!) 

 coordinated with that of the continent. Such an enter- 

 prise as that of Sir David Gill in measuring an arc 

 of the meridian from the Cape to the northern liemi- 

 sjjhere would not be left to private initiative. 



If the topographv of vast territories is still i 

 fectlv known, their geology is practically untouched. 

 .Africa differs from neighbour! ntr continents in being 

 all but an island. It seems to be the part of the 

 earth's surface which has been least disturbed bv 

 volcanic action. It has preserved a structure of 

 great antiquity. Thoroughly understo<id, it would 

 throw light on an early chapter of the histor\' of the 

 earth. 



In the .southern hemisphere British maritime activity' 

 1^ dominant. .A knowledge of the meteoroloirv of it« 

 oceans is a neces.sarv condition of their secure navi- 

 tfation. Sir Charles Bruce, in his " Bn^nd Stone of 

 Empire." has eiven a striking account of what has 

 been af^complished towards it bv the Mauritius 

 Meteorolocrical Observatory. .Such a measure of un- 

 doi'bted success should stimulate further endeavour 

 and the provision of other station* Tt oi-ght to be 

 predict the d ^ of India 



