632 REPORT— 1903. 



dently of such action ; and now these observers have found that in the case of 

 ladium m air this light gives the spectrum, line by line, of nitrogen. Is it possible 

 that the enveloping nitrogen has had its atoms so harried by the activity of the 

 radium as to give a response hitherto only awakened by electric discharge ? The 

 ability to obtain such a response opens up a new possible interpretation of 

 these spectra, which hitherto have been assumed, with our laboratory experience 

 only to guide us, to have required for their production temperature above a red heat. 

 If further observation should confirm this, the hydrogen, the hydrocarbon, and 

 possibly even the sodium or iron spectrum that has been observed, may have come 

 from cold atoms ; and it is not even quite beyond the limits of imagination to picture, 

 not from the comet matter itself, but from loose residual and highly attenuated 

 matter through which the comet is passing. 



There is one other feature of this remarkable observation of equal interest. 

 The lines of the spectrum were not exactly in their proper place, but were all 

 shifted towards the red end of the spectrum about twice the distance between the 

 D lines. If only one or two lines had been so observed a difierent origin might 

 well have been suspected ; but when the whole series are faithfully reproduced 

 it is reasonable to look upon the spectrum as modified to that extent as though 

 the works of the nitrogen atom had not only been set in movement, but had been 

 loaded with the radium emanation. 



Before dismissing these random speculations on the possible connexion 

 between radio-activity and comets I would ask your leave to refer once more to 

 Bredechin's conclusions. He has found that it is merely necessary to postulate 

 three kinds of matter, issuing from the nucleus with three initial veloeiti*-?, 

 and subject to repulsion from the sun with three sets of forces of repulsion — i.e. 

 as compared with ordinary gravitative attraction — for the whole of the phenomena 

 of all sorts of comets to be very completely accounted for. His highest initial 

 velocity is only about fi.ve miles a second, and his lowest about a quarter of a mile 

 a second. His highest repulsion, after deducting gravitative attraction, is only 

 eleven times gravity, and his lowest only a fifth of gravity. If, then, with such 

 velocities and forces the phenomena can be exactly acc£)unted for, it would seem 

 futile to consider the possibility of initial velocities from 4,000 to 80,000 times as 

 great and effective repulsions of a corresponding order being able to produce 

 effects with anything in common. This is not necessarily the case, for with the 

 comparatively slow separation of the atoms of Bredechin's matter from the nucleus, 

 each one describing its own hyperbola convex to the sun, the tail at any moment 

 represents the then position of any number of atoms which left the nucleus for 

 some distance back, whereas with the enormous velocities and effective forces now 

 discussed the comet moves so slowly in comparison that the tail would practically 

 represent the path at the time. 



It has taken me far longer to throw out this not very luminous ray than 1 had 

 expected or than it is worth. I fear that it is a sort of ray in which the ratio of its 

 dead weight to its vitalising charge is too small to enable it to penetrate the 

 lightest screen of examination. 



These are the days of rays, and now before we have quite become familiar 

 with the rays of radio-active bodies Blondlot has presented us with N rays, which 

 issuing from the mantle of an incandescent gas burner penetrate wood or 

 aluminium, and then increase the light without increasing: the heat of hot bodies 

 on which they fall. 



-"o 



Passing now from the amusement of speculation to more serious duties, I find 

 myself confronted with the difficulties that prevent us in this country from 

 succeeding as we used to do in the international struggle — a struggle the issue of 

 which is daily becoming more and more a question of iDrains, of education, of skill 

 and enterprise in manufacture—and finally of that great virtue extolled by the 

 President of the United States, strenuousness. 



It is the duty of everyone who sees the way in which we are being outstripped 

 in the race to do what in him lies to scrape off the rust which is clogging our 

 •educational machinery. I now refer to the defects which hamper the intellectual 



