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NATURE 



[August 4, 1904 



LETTERS TO THE EDITOR. 



{The Editor does not hold himself responsible for opinions 

 expressed by bis correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 JVo notice is taken of anonymous communications] 



Octopolarity and Valence. 



Of the elements and their compounds there is a general 

 property which is related to the peculiarities of their 

 periodicity in a remarkable manner. This property is that 

 of crystallisation, and in the isometric system is seen in its 

 least complicated form. Among the conceivable causes 

 which might act to produce the regular arrangement of 

 particles evidenced in crystals, the view that considers the 

 atom as having eight fields of polarity radiating from it, 

 corresponding to the eight corners of a cube or the eight 

 faces of an octahedron, agrees well with a wide range 

 of facts. When an isometric crystal is heated and cooled 

 ■under suitable conditions, polarity is developed in this 

 manner. Four of the centres of polarity are positive and 

 four are negative ; the angle between the direction of like 

 poles is 109° 28'. 



Consider the bonds of chemical affinity or valence in the 

 first two series of the elements. Helium, the first element 

 of the periodic table proper, is devoid of affinity to combine ; 

 the valence of lithium, the first member of the first series, 

 is one, of beryllium two, of boron three, and of carbon 

 four. From stereochemical considerations it is believed 

 that the four bonds of affinity in carbon are alike, and are 

 disposed about the centre of the atom at angles of loq" 28' 

 apart, as are the four portions of the isometric crystal that 

 have the same polarity. In the first four members of the 

 series there is a regular increase of one bond of affinity to 

 each succeeding element, and all are of the same character. 

 In the ne.xt member, nitrogen, the valence is five, but one 

 is of a diiTerent character, while four are alike in all respects 

 as in compounds of the type NH,|C1. Nitrogen forms com- 

 pounds also on another type of valence, as in NH3, where 

 it is trivalent. These three bonds of affinity are of the 

 same character. Two bonds of opposite character, one 

 positive and one negative, are rendered latent, a self- 

 balanced pair. Oxygen, the next member, has only two 

 active bonds and also latent pairs, but these are more 

 difficult to render manifest than those of nitrogen. 

 Fluorine has one active bond of affinity, and gives some 

 evidence of possessing latent pairs also. The valence of 

 neon, the last member of the series, is zero, being similar 

 to helium. The next series of eight, Na, Mg, Al, Si, P, 

 S, CI, and A, corresponds perfectly in regard to the number 

 of active bonds of affinity with the preceding series, while 

 the latent pairs are more easily rendered manifest in com- 

 bination, with the exception of argon, which has not been 

 made to enter into chemical union. The series exhibits these 

 valencies : — 



Na, Mgj AI3 Si^ 



Thus the arrangement of the pyroelectric poles of an 

 isometric crystal may serve to illustrate the changes of 

 valence of the elements with increment of atomic weight. 

 It would seem that when all eight polar faces have received 

 the increment there is perfect balance, and the structure 

 is no longer chemically active, as in helium, neon, and 

 argon. Each of the first four members, Na, Mg, Al, and 

 Si, has a definite valence which does not change, while 

 P, S, and C! have, beside the maximum valence, i, 2, and 

 3 pairs respectively which can be rendered latent in pairs, 

 as a positive field of force neutralising the effect of a 

 negative field. 



With this clue as to the nature of the increment of atomic 

 weight, a conception of the structure of the atom can be 

 formed which presents many remarkable and unexpected 

 points of agreement with the system of the elements. If 

 the increment of atomic weight or the principal factor of 

 increment is due to addition of a ring, and no other structure 



NO. 18 14, VOL. 70] 



be found to adapt itself, the original atom form will 

 consist of eight rings arranged like the eight circles in- 

 scribed on the faces of an octahedron. That rings will unite 

 to form this as a structure of maximum stability will 

 depend on their possessing the following properties. The 

 material of the ring is a conductor of electric current, and 

 a field of magnetic force permeates the space about the 

 ring. The magnetic field on one side of the ring plane is 

 of opposite polarity to that of the other side. The ring is 

 elastic, and in vibrating would have a number of equi- 

 distant non-vibrating nodes about its circumference, separ- 

 ated by internodes of vibration. Briefly it is an elastic, 

 current-bearing ring in rapid motion. After examining all 

 conceivable combinations of this ring, it became apparent 

 that the structure of maximum stability resulting from com- 

 bination of these rings is that of eight rings arranged like a 

 the eight circles inscribed on the faces of an octahedron. 

 The essential condition of stability is that contact of rings 

 should be at non-vibrating nodes, otherwise the energy of 

 vibration would drive them apart, also that the flow of 

 electric current in contiguous rings should be in the same 

 direction in each ring at the point of contact, otherwise 

 there would be magnetic repulsion. 



Rings may be added to the eight-ring structure in the 

 order indicated above from study of the crystal and the 

 change of valence in the series, and the stability of the 

 structure retained or even increased. As the external 

 arrangement remains the same, the first rings are forced 

 inward, and as more are added the further in these first 

 rings become, but they will not be strongly vibrating like the 

 outer rings, and so can come in stable contact at any point 

 of the circumference. 



As there would very evidently be a limit to the number 

 of series possible, a wire model was made of rings to deter- 

 mine this. When eighty rings were used, forming nine 

 series of eight members each, after the original eight-ring 

 form, no more rings could be added. The four innermost 

 rings had come in contact and would go no further in, being 

 arranged like the four circles inscribed on the faces of a 

 tetrahedron. If a free ring was laid on the surface of the 

 eighty-ring structure, it would be first attracted strongly 

 by the magnetic field, and instead of being held in stable 

 combination would be driven off by vibration of the inter- 

 nodes of the ring where it was laid. Such a structure would 

 spontaneously lose rings, and these liberated rings, in 

 accordance with their properties, would form the original 

 eight-ring structure corresponding to helium. 



FR.4NK A. Healy. 



681 1 Anthony Avenue, Chicago, III. 



Botanical Nomenclature. 



.\n event of considerable importance to botanists is the 



publication of a new code of botanical nomenclature, 

 prepared by a commission appointed by the Botanical Club 

 of the .'\merican Association for the .Aavancement of Science. 

 This document, which has the approval of a large number 

 of the leading botanists of America, appears in the Bulletin 

 of the Torrey Botanical Club for May, being printed in 

 three languages. The commission proposes to move in the 

 Vienna Botanical Congress of 1905 that the code now 

 offered be adopted bodily, and all other articles abandoned. 



In these circumstances, it must be admitted that dis- 

 cussion is opportune. The authors state that they have 

 found the Paris code of 1867 unsatisfactory, because " many 

 important principles are either not recognised, or else given 

 altogether too meagre consideration, and that there is a 

 want of definite and exact statement, which leads to 

 ambiguity." While there is very much in the new code 

 to approve and admire, it seems to me that upon certain 

 points these very words are exactly applicable to it. With- 

 out attempting to cover the whole ground, I desire to refer 

 to a few special points. 



(i) " Names published for primary subdivisions of species 

 are treated as subspecific names, however designated bv 

 their authors." One example given is Zizia aurea, var. 

 Bebbii, Coult. and Rose. No example is given of a plant 

 designated a form, or of mutation; are these intended to be 

 excluded? It seems evident that many plants designated 

 varieties are not in any sense subspecies, and so to consider 



