132 



NA rURE 



IDcc. 9, i,S86 



To put this in other words, we can obtain from thehe.it 

 of formation of cuprous chloride, or of cupric chloride, 

 an approximate calculation of the difference of electric 

 potential between the copper atom and the chlorine atom 

 in the two salts. 



Now, as already stated, the heat of formation per 

 chlorine atom is nearly the same ; that is, the difference 

 of potential between the copper and chlorine is nearly 

 the same in both salts. What follows from this? 



It follows that, in doubling the electric charge on the 

 copper atom, the potential is not also doubled. This 

 means, therefore, that the capacity for electricity of the 

 atom is increased at the same time. This conclusion is 

 not quite certain, as our information is still too scanty on 

 the actual differences of potential in the case of these two 

 salts ; and, further, we do not know what fraction of it 

 belongs to the chlorine atom ; but, on the whole, the facts 

 we have point to the above conclusion, and it is at any 

 rate a subject well worthy of study to determine whether 

 the capacity of the atom for electricity can vary or not. 



Passing from this, I wish to point out another very 

 obvious but nevertheless important deduction to be made 

 from the facts of electrolysis. 



We have recognised that the difference between mono- 

 valent and divalent copper consists in the doubling of the 

 charge upon the atom. This again may be due to some 

 profound change in the atom itself, but it is at any rate 

 the obvious and marked distinction ; we have copper in 

 both cases, but double the electrical charge in one case 

 over that in the other. 



If we searched among the elements, could we find two 

 series of salts more completely different in their nature 

 and properties than the cuprous and cupric salts ? 



I venture to say that, if we did not know we could 

 derive the same element from both, we should assume 

 them to be derived from two different elements, and 

 assign them very diflerent places in Mendelejeff's table. 

 Many other examples of the same thing will occur to 

 everybody, namely, that alteration of the electrical charge 

 on the atom is accompanied by profound alteration in the 

 nature of its compounds, and is therefore probably the 

 cause of this alteration. 



Up to this point 1 think my deductions are fair and 

 obvious deductions from the facts of electrolysis. I 

 wish now to suggest a possibility, I can call it no more, 

 which if true will considerably alter our views of the 

 lacts of chemistry. We have found the importance of 

 alterations of electrical charge in altering the properties 

 of an atom as shown in its compounds. 



We already believe that variations in atomic weight are 

 closely allied with the variations in the properties of the 

 atom as shown in its compounds. 



Are there, then, two things which condition the chemical 

 properties of an atom, or is there only one.'' 



Let us look again for an instant at the facts of electro- 

 lysis, and let us take the electrolysis of hydrochloric acid 

 as our example. 



At present we state the facts thus : — Every molecule of 

 hydrochloric acid consists of one atom of chlorine and 

 one atom of hydrogen, the chlorine atom weighing 355, 

 the hydrogen atom weighing i. On passing a current, 

 each molecule is split into these two atoms, each atom 

 carrying a unit charge of electricity. 



Is it not just possible that we may some day state the 

 facts thus : — .'\ molecule of hydrochloric acid consists of 

 one molecule of hydrogen weighing l combined with 35'5 

 molecules of chlorine each weighing I. On electrolysis, 

 the chlorine atoms are split from the hydrogen atom, the 

 chlorine atoms each carrying unit charge of electricity, 

 and the hydrogen atom carrying 35*5 charges of elec- 

 tricity.' 



If this is the truth, then all the atoms of the elements 

 are of the same weight, and probably are made of 



' No one need quibble about the 35-5. 



the same "stuff,'' and we have two, and only two, 

 things which condition the properties of the atom — 

 namely, its electrical charge and its electric potential, and 

 Mendelejeff's table becomes a statement of the periodic 

 relationship between these. 



In suggesting this vague possibility, I do not wish to 

 obscure the first part of the paper, which consists, 1 

 believe, of perfectly legitimate deductions from the facts of 

 electrolysis. 



I have purposely avoided giving many examples, as 1 

 have been dealing with such familiar and common-place 

 chemical reactions that plenty of examples will at once 

 occur to every reader ; and sufficient has, I think, been 

 said to show at any rate the importance of experimental 

 inquiry into this subject, and the probability of consider- 

 able modifications of our views of chemical facts in the 

 near future. 



The new way of looking on valency, which we owe to 

 Prof Helmholtz, may, as I have already pointed out, 

 completely alter our conception of the nature of an un- 

 saturated carbon compound, and of the process by which 

 saturation takes place ; and probably as investigation 

 proceeds in this department it will become necessary to 

 re-dissolve our chemical facts and crystallise them out 

 in completely new mental concepts, while doubtless the 

 ideas associated with the graphic formula pass away and 

 leave not a wrack behind. A. P. L.\urie 



MUSIC AND MA THEM A TICS 



YESTERDAY afternoon meeting at a friend's house a 

 lady visitor to C)xford who was to sing that evening 

 at one of the hebdomadal concerts in Balliol College, 

 and the conversation happening to turn on the gifted 

 mathematical lady Professor in the University of Stock- 

 holm, my thoughts shaped themselves, as I was walking 

 home, into the following lines, which, if likely to interest 

 any of your readers, I shall be happy to see appear in the 

 world wide-diffused columns of NATURE. 



New College, November 15 J. J. SvLVESTER 



Sonnet 

 To a Voti/ii; Lady about to si>?if at a Suiiday Evening 



Conceit in Balliol College 

 Fair maid ! whose voice calls Music from the skies 

 Weaving amidst pale glimpses of the moon 

 Tones with fresh hues of glowing fancy strewn 

 And soft as dew that falls from pitying eyes- 

 Let from their virgin fount those accents rise 

 That bid sad Philomel suspend her tune. 

 Thinking the lark doth chant his lay too soon- 

 Wliose else that trill u'liiik with her own note 7'ies / 

 To her whose star shines bright o'er Maelar lake 

 And thee who beautifi'st glad Isis' shore 

 Grant ! I one joint harmonious garland bind : 

 Thou canst with sounds our senses captive take - 

 She the true Muse, fond poets feigned of yore, 

 Strike Heaven's own lyre, Nature's o'erruling mind. 



XOTES 



Mr. Harold B. Dixon has been appointed Professor of 

 Chemistry and Director of the Chemical Laboratories at Owei>.s 

 College, Manchester. 



The Ox/nnl A/agiz^iitf annoimces that Prof Burden .Sander- 

 son and Mr. Gotch are going to spend their Christmas v.ication 

 at Arcachon, where there is awaiting them a large tank full of 

 torpedoes. It looks forward with interest to the publication of 

 the results of the Oxford physiologists' holiday, remarking that 

 " to the research will be added the pleasing excitement of 

 danger ; for if incautiously handled these torpedoes will give the 

 physiologi-t a shock, compared with which the agonies of scores 

 of vivisected rabbits are as nothing." Of course this is not true. 



i 



