Mav 9, 1 90 1 



A^^ TURE 



29 



LETTERS TO THE EDITOR. 



{The Editor does not hold himself responsible for opinions ex- 

 fres:.cd by his correspondents. Neither can he undertake 

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

 manuscripts intended for this or any other part of Naturk. 

 No notice is taken of anonymous communications.] 

 Scope of the Royal Society. 



As a general principle it is not desiral)le to make the affairs of 

 the Royal Society a subject of public tliscussion. The question 

 to be submitted to the consideration of the fellows on May 9 is, 

 however, of sufficient general interest to justify an exception. 



The notice given has been short, and I am unable to be 

 present. No vote is to be taken. It will, therefore, not be too 

 late to draw attention to some facts which appear to me to have 

 been overlooked. 



The .starting point of the matter as it is presented to the 

 Society is contained in the following statement : — 



"The Society exists for the promotion of Natural Knowledge. 

 The interpretation of the term ' Natural Knowledge,' according 

 to the present practice of the Royal Society, assigns to it a range 

 from Mathematics to the various Biological sciences, and this 

 secures the inclusion of the scientific study of man in his biological 

 relations. It has been argued that this range might be properly 

 increased by the inclusion of the scientific study of man in his 

 reasoning, social and historical relations. It may, indeed, be 

 further contended that the Society should include in its scope all 

 branches ol Natural Knowledge which are capable of consecutive 

 and ordered development. Such a test would permit the inclusion 

 of subjects such as Psychology, Economics, Historical Science 

 and Philology in the widest sense of the term, which, under the 

 present jiractice of the Society, may be deemed excluded, but 

 which, when pursued as they now are by the most capable 

 students, in a scientific spirit and by scientific methods, do fall 

 within the domain of Natural Knowledge. The investigation, 

 for instance, of the phenomena of the origin and variations ot 

 human speech, of the beliefs and customs of primitive man, of 

 the production and distribution of wealth, of the laws which 

 govern the development of political societies, is an investigation 

 into natural phenomena in a sense which the progress made in 

 our Conceptions of nature during the last two centuries seems to 

 justify." 



Now I have always understood — and my impression is con- 

 firmed by the highest authority— that admission to the Society is 

 actually open to any one who has promoted Natural Knowledge, 

 in whatever field, by scientific methods. The open door may 

 not have been taken advantage of, but I am not aware that there 

 is the smallest ground for believing that it has ever been closed. 

 What I wish to draw attention to is that though the actual 

 representation of the subjects enumerated above may not have 

 been as full as it might have been, I am unable to agree that 

 they, "under the present practice of the Society, may be deemed 

 excluded." A rather cursory inspection of the names of those 

 who have been fellows, or have been elected during the last 

 twenty years, confirms my opinion. Under Economics I find 

 Heywood, Newmarch, Sir James Caird, Jevons, Palgrave, 

 Sir Robert Giffen, Charles Booth and Shaw-Lefevre. I 

 am under the impression that for the period this is a very fair, 

 if not actually adequate, representation of economic science. 

 Historical Science, I presume, must be taken to include archx- 

 ology and ethnography, otherwise these will have again to be 

 " deemed excluded." Assuming that this is not so, I find the 

 names of General Pitt- Rivers, Sir Augustus Franks, Canon 

 Creenwell, Tylor, Penrose and, in the list now recommended 

 by the Council, of Arthur Evans. Of Historians, in a restricted 

 sense, I find Dean Stanley and Sir Henry Howorth, and, if 

 Privy Councillors are included, of Bryce and John Morley. And 

 with regard to the class of Privy Councillors, it is to be re- 

 marked that although any one is eligible it is apparently rare 

 for any to be elected without something more than mere 

 political qualifications. Philology has been more weakly 

 represented ; still, I find the names of the Dean of Canterbury, 

 Alexander Ellis, Sir Henry Rawlinson and Bryan Hodgson. 

 And if Psychology finds its only representative at the moment in 

 Lloyd Morgan, it is, I believe, an open secret that Herbert 

 Spencer might, had he thought fit, have been a fellow of the 

 Society. 



Besides the names I have enumerated, I am very much dis- 

 posed to doubt if a score can be enumerated, or perhaps even 

 half that number, of others in the same fields who during the 



NO. 1645, VOL. 64] 



last twenty years possessed conspicuous claims to admission to 

 the Society. Nor can I believe that if men like the late Bishops 

 of Oxford and London or l-'reeman had been willing to become 

 candidates there would have been any likelihood of their being 

 unsuccessful. Like Thorold Rogers, whom I often urged to 

 allow himself to be proposed, they may not have desired 

 admission. W. T. Thi-sei.ton-Dyer. 



Kew, May 6. 



The Spectra of Carbon Monoxide and Silicon 

 Compounds. 



A I'Ai'ER published by Prof. Hartley {Proc. Roy. Soc. vol. 

 Ixviii. pp. 109-112, March, 1901) reminds me of some 

 observations on the spectra of the compounds of silicon with 

 fluorine and hydrogen (SiFlj and .Silij), made by me several 

 years ago and published in IViedemanii' s Annalcn[\a\. xxi. pp. 

 427-437, 1884). As they seem to be not without some interest, 

 and a definite explanation of them has, so far as I know, not 

 been given till now, I may be permitted to give here a short 

 account of the principal contents of my little paper. 



A vacuum tube filled with SiFI,, and procured from Geissler 

 Nachfolger, in Bonn, showed a spectrum of which the greatest 

 part consisted in the well-developed band spectrum due to 

 carbonic oxide, besides which there appeared the eight beautiful 

 blue lines, or rather stripes, that seemed (at least then) to be 

 characteristic of SiFlj. Now there is nothing wonderful about 

 the presence of traces of the carbonic oxide spectrum in a 

 vacuum tube, as is well known, but in our case it was so pre- 

 dominant, as if one had not simply to deal with impurities, but 

 on the contrary, as if it was the principal part of the phenom- 

 enon. Intending to clear up the circumstances, I tried to pre- 

 pare vacuum tubes from which the presence of carbonaceous 

 matter, as well as of air and moisture, were as much as possible 

 excluded, and finally the SIFl, gas was developed from a mix- 

 ture of pure glass and flourspar powder and also purest sulphuric 

 acid in an apparatus composed entirely of glass and sealed directly 

 to a Toepler mercurial pump. All stop cocks and sliding pieces 

 that want greasing were totally avoided. Nevertheless, the 

 carbonic oxide spectrum remained in its very predominant 

 position ; at low pressures it was even present almost alone, as if 

 one were working on a carbonic oxide tube containing some 

 impurities due to silicon combinations. Sometimes, it is true, 

 the carbonic oxide bands were less brilliant, and the blue stripes 

 (belonging to SiFlj ?) more prevailing, from what cause I do not 

 know, but still the carbonic oxide spectrum aKvays remained 

 well visible. Perhaps it is worth mentioning that sometimes 

 there were seen four additional lines situated more towards the 

 violet end of the spectrum, and occasionally, also, some green 

 ones. Also the well-known swan spectrum could be obtained, 

 especially when the discharges of a Leyden jar were sent through 

 the vacuum tube. Even tubes illuminated in the well-known 

 manner without the use of electrodes still showed the carbonic 

 oxide spectrun; in its predominant position. If some traces of 

 OX) gen had been developed from moisture, which, as is welt 

 known, it is almost impossible to totally remove from the glass 

 apparatus used,' and this had, by combining with some carbon- 

 aceous compound present in the tube given rise to some traces of 

 carbonic oxide, then one could, so far as I know, only have 

 expected a rather faint spectrum due to it. I do not know if 

 the suggestion of carbon being contained in the element silicon 

 is at all acceptable, according to present knowledge, but at all 

 events the brilliant appearance of the CO bands awaits, as I 

 believe, a sufficient explanation. 



In a rather high vacuum this CO spectrum is not seen, but 

 there are visible (except lines due to mercury, hydrogen, &c. ) 

 some lines also observable in highly exhausted tubes filled with 

 carbonaceous compounds, but which, as I found in the latter case, 

 only appear when luminous points are seen at the electrodes and 

 the glass covers that partially surround them. As I found those 

 lines to coincide with lines observed in the spark spectrum of 

 SiFlj at high pressures, this so-called vacuum sped rum probably 

 belongs to some silicious matter evolved out of the above- 

 mentioned glass covers by the action of the said bright points. 



Under suitable conditions SiHj also showed the carbonic oxide 

 and swan spectrum, and as well the one ascribed to hydrogen, 

 this latter especially being seen at lower pressures, whilst of a 

 silicon spectrum nothing was observable. Only at higher 

 pressures, by the aid of spark discharges, some of the lines were 

 obtained that had been seen formerly in the spark spectrum of 

 SiFlj. 



