82 



NATURE 



[September 25, 1919 



modern study of genetics gives no means of distin- 

 guishing a new factor from one long in existence. 

 He suggests tfiat the mutations studied bv De Vries 

 in plants, and the modifications obtained by Castle 

 in mammals, are due to the combination of pre- 

 existing factors, while the famous mutations in flies 

 elucidated by Morgan 'are in the nature of modal 

 fluctuations having no definite cumulative value." 

 Prof. Walton's own definite contribution in this paper 

 is found in his summary of the direction of axial 

 rotation in Euglena and other Protozoa which " is 

 best explainable on the basis of the apparent east- 

 west motion of the sun having influenced the move- 

 ment of the organs of locomotion." This seems an 

 insecure foundation for such a generalisation as the 

 author's statement that "the primary factors in evolu- 

 tion are environmental, and thus dynamic." 



G. H. Carpenter. 



CHEMISTRY OF "BURGUNDY MIXTURE." 

 TTHE chemistry of "Burgundy mixture" is prac- 

 -•■_ tically important, because to give it the greatest 

 efficiency it should possess a maximum fungicidal 

 power and a minimum potentiality for injuring foliage. 

 The reaction of sodium carbonate and copper sulphate 

 solutions has been studied by Pickering and by Ravaz, 

 but, according to a paper contributed to the August 

 Journal of the Chemical Society by Messrs. Robert L. 

 Mond and C; Hcberlein, the problem is more complex 

 than they considered. The latter authors have studied 

 the reactions of copper sulphate with varving propor- 

 tions of sodium carbonate and of sodium hydrogen 

 carbonate; have determined the amount of absorbed 

 sodium carbonate and the ratio of copper oxide to 

 carbon dioxide in the various precipitates and the 

 amount of basic copper sulphate in the mixtures ; and 

 have studied the solvent action of carbon dioxide and 

 the change of the colloidal precipitate to a crystalline 

 form. As a result of their experiments Messrs. Mond 

 and Heberlein conclude that three distinct copper 

 compounds are formed when sodium carbonate and 

 copper sulphate solutions are mixed :— (i) Insoluble 

 hydrated basic copper carbonate (the bulk of the pre- 

 cipitate) ; (2) insoluble hydrated basic copper sulphate; 

 and (3) soluble basic copper sulphate in the form of 

 a hydrosol; the proportions of which vary with the 

 conditions of precipitation. One molecule of copper 

 sulphate is completely transformed by 003 molecule 

 of sodium carbonate instead of the one molecule 

 theoretically necessary. In a i per cent, mixture of 

 copper sulphate and sodium carbonate (in the propor- 

 tion 1:0-93 mol.) made at 15°, 96 per cent, of the 

 copper is present as soluble basic sulphate, the basic 

 carbonate contains copper oxide and carbon dioxide 

 in the ratio 22: i, the insoluble basic sulphate con- 

 tains copper oxide. and sulphur trioxide in the ratio 

 15 : I, the precipitate contains absorbed sodium car- 

 bonate in the proportion of i part to 74 of copper 

 oxide, and 524 per cent, of the carbon dioxide is 

 evolved. At higher temperatures more carbon dioxide 

 is evolved, all being expelled on boiling. The amount 

 of basic sulphate formed decreases as the proportion 

 of sodium carbonate Increases, the proportion in solu- 

 tion (but not that of the basic carbonate) increasing 

 with the amount of free carbon dioxide. .At first the 

 precipitate is whollv colloidal, but eventually it 

 becomes crvstalline, the colloidal condition apparently 

 being conditional on the absorbed sodium carbonate. 

 The transformation is accelerated by free copper sul- 

 phete. carbon dioxide, or sodium hydrogen carbonate, 

 but retarded by sodium carbonate or 002 per cent. 

 of glue. 



NO. 2604, VOL. 104] 



MTHER AND MATTER: BEING REMARKS 

 ON INERTIA. AND ON RADIATION, 

 AND ON THE POSSIBLE STRUCTURE 

 OF ATOMS.T' 



Part II. — ^The Possible Structure of Atoms and 



THEIR Radiation. 

 jLJOW, then, are we to explain the different kinds 

 ■*■-•• of matter? Here we enter upon territory so 

 recently annexed as to be still very debatable;' but 

 progress has been and is still being made, and it is 

 only through the work of recent explorers that we 

 can attempt to answer the question at all. It is 

 invidious to select names, but I must mention 

 Rutherford, Soddy, Barkla, Bragg, Moselev, Nichol- 

 son, and Bohr, among many others. M'oseley— as 

 brilliant as any of them, 'and patriotically ' self- 

 sacrificing like all our splendid vouth—was' killed, 

 alas! by a Turkish bullet at Gallipoli ; though not 

 before he had made an immortal discovery. How 

 much more might he not have accomplishe'd had it 

 not seemed good to evil Powers to impose by force 

 their dominance on the world ! 



To give a certain and definite answer to questions 

 about the structure of the atom is premature. I can 

 only state the answer which at present tentativeh- 

 appeals to me and, I think, to others. Your professo'r 

 of natural philosophy (Sir J. J. Thomson) is lecturing, 

 I. see, on Saturday afternoons concerning spectro- 

 scopic evidence on this great subject, and he will, no 

 doubt, carry the matter further. 



Meanwhile, and very briefly, the idea about the 

 atom which at present seems most likelv to be on 

 the path towards truth is a central positive nucleus 

 surrounded by a system of negative electrons— so 

 much is pretty certain — while according to one 

 theory the system is composed of revolving electrons 

 moving under an inverse-square law in regular orbits, 

 very like the sun and planets. The orbital move- 

 ment is governed by electric force instead of by 

 gravitation, but the laws of motion, and the per- 

 turbations which may be caused bv outside forces, 

 are very like those familiar to astronomers. 



-According to Moselev 's experimental counting and 

 Bohr's theory, hydrogen seems to be like a sun with 

 one planet, just a positive and a negative electron, 

 the two being equal electrically, but differing in 

 inertia, the positive being the more massive, though 

 probably for that reason the smaller or more concen- 

 trated of the two. Helium seems to have two central 

 unbalanced positive charges and two revolving nega- 

 tive ; lithium, three of each ; beryll.ium, four; boron, 

 five; carbon, six; nitrogen, seven; oxygen, eight, 

 and so on, according to the number of the element 

 in Mendel^eff's series — a number something like half 

 the number expressing its atomic weigfit. 



The number of positive atoms in the nucleus was 

 counted for several elements by Rutherford, and the 

 number of negative corpuscles in the orbit was counted 

 by Moseley; the two numbers agree. Normal atoms 

 are therefore electrically neutral, so that their 

 externaf electric attraction at any reasonable distance 

 is nil ; but it is supposed that at atomic or molecular 

 distances the outer or orbital electrons which can 

 interlock with those of others determine the atom's 

 chemical affinity and all the chemical behaviour of 

 the .substance. .An atom with one or two outlving 

 planets — let us surmise — would be an active chemical 

 element, a monad or dyad perhaps. .An atom with 

 a close-grouped, self-contained system would be an 

 inert element of the argon-neon-helium series. These 



1 Amph6ed from a discourse drlivc'cd at the Roval Institution on 

 Fridav. Febni,iry 28, 1919, by Sir Oliver J. Lodge, F.R.S. Continued from 

 p. 19 (September 4). 



