7oo 



NATURE 



\Qct 31, 1878 



theoretically solved. On February 14, 1876, Gray re- 

 gistered this invention at the American Patent Office, 

 under the title of "a means of transmitting and receiving 

 vocal sounds telegraphically," and in his caveat he gives 

 an exact drawing of the method he adopts, and which 

 we here reproduce. 



Curiously enough, on the very same day, there appears 

 the first documentary evidence on behalf of Prof. Graham 

 Bell, and this, too, is for a patent granted to Bell — not, 

 however, for the electric transmission of speech, but 

 "for certain new and useful improvements in telegraphy." 

 These improvements consist in the employment of in- 

 duced undulatory electric currents, and form one of the 

 numerous practical applications of Faraday's famous 

 discovery of magneto-electric induction. By the ap- 

 proach and recession of the prongs of a magnetised 

 tuning-fork, or by the oscillation of a magnetic dia- 

 phragm, alternating currents were generated in an 

 adjacent coil of wire. This is the essence of Bell's 

 patent, the advantages claimed by the use of such 

 undulatory currents being increased speed of telegraphy 

 and the possibility of multiplex telegraphy. Nothing is said 

 about the transmission of speech till near the end of the 

 specification, when it is stated that " one of the ways in 

 which the armature may be set in motion [to generate 

 these currents] is the wind. Another mode is the human 

 voice, or by means of a musical instrument." So that, 

 of the five claims made by this patent, the last, and appa- 

 rently quite subsidiary one, was " the method of trans- 

 mitting vocal or other sounds telegraphically." A diagram 

 of the arrangement devised for this purpose accompanies 

 the specification, which arrangement, however, upon 

 subsequent tr»l, proved, as Prof. Bell stated in 

 London, "unsatisfactory and discouraging." It is 

 not, however, fair to conclude, as Mr. Prescott has 

 done in the words we quoted earlier, that Bell 

 had to resort to Gray's method before he was enabled 

 to transmit speech electrically. The fact seems to be 

 that some little time after he obtained his patent. 

 Bell turned his attention to the development of the 

 speaking telephone, and by a modification of the method 

 he originally proposed, arrived at some important results 

 which were published on May 10, 1876, in the Proceed- 

 ings of the American Academy of Arts and Sciences. 

 Sir W. Thomson heard articulate sounds transmitted by 

 this telephone in August, 1876, but the instrument was then 

 very imperfect, nor was it until the early part of 1877 that 

 the speaking telephone may be said to have been a fait 

 accotnplij in May, 1877, it was successfully tried between 

 Providence and Boston, places forty-three miles apart. 

 There seems reason to believe that the important im- 

 provement of the substitution of permanent magnets for 

 electro-magnets was made at the suggestion of Prof. 

 Dolbear, and that Professors Peirce, Blake, Channing, 

 and others contributed valuable modifications of the 

 original design, until the Bell telephone assumed its 

 present simple, elegant, and handy shape, growing in 

 efficiency as it diminished in size and complexity. 



Thus it will be seen both Gray and Bell can fairly 

 claim the discovery of the principle of the articu- 

 lating electric telephone. Gray solved the problem first 

 theoretically, Bell first practically ; the former proposed 

 to vary the resistance of the circuit without changing the 

 electromotive force ; the latter varied the electromotive 

 force without changing the resistance. And although 

 Gray's method was only partially successful in operation, 

 owing to his employing an electrolytic resistance, it is a 

 method capable of yielding more striking results, owing 

 to the use of more powerful currents. But where Gray 

 failed, Edison has succeeded, and in another article we 

 propose to trace the connection of this remarkable in- 

 ventor with the subject of electric-telephony, up to his 

 splendid discovery of the carbon telephone. 



W. F. Barreit 



COLOUR BLINDNESS IN RELATION TO THE 

 HOMERIC EXPRESSIONS FOR COLOUR'' 



II. 



CO far as I can follow Mr. Gladstone's investiga- 

 ^ tions, it appears to me that Homer has exactly ful- 

 filled all the conditions mentioned in the previous article. 

 As many references are made to natural objects which 

 have the same colours now as they had in his time, I am 

 able, with my colour-blind experience, to judge what 

 sensations they would present to his eyes, supposing him 

 colour-blind, and I can thus form a judgment of the 

 appropriateness and consistency of his descriptions on 

 that hypothesis. I can clearly trace the existence of two 

 groups of epithets, which, so far as I can see, are kept 

 fairly distinct, and the words in which are never mixed 

 up with the ideas belonging to the contrary group. The 

 epithets are — 



For the group of the yellow sensation : ^av66s, ipvGpos, 

 <fo'ivi.^, podofis, x^<>>P^s, Kvdveos, and perhaps oii/o^. 



For the group of the blue sensation : Trop^vptos and 



lodSrjs. 



For neutral sensations, irrespective of the words \(vkos 

 and p.(\as (which may be left out of consideration alto- 

 gether, the use of them being normal, and the vision of 

 the colour-blind in regard to them being normal also) 

 there is the epithet jroXidf, on v.'hichan important element 

 of the argument hangs. 



We will now take these various words seriatim, and 

 compare what Mr. Gladstone says of their application 

 with the use that might be expected to be made of them 

 by a colour-blind writer. 



Savdos. 



Liddell and Scott's translation of this word is "yellow 

 of various shades, often with a tinge of red, chestnut, 

 auburn." Mr. Gladstone (N. 380) considers it, as used 

 by Homer, to be a true word of colour, and that its appli- 

 cations are especially consistent. 



It is used principally for human hair, and to the colour- 

 blind «// varieties of hair, except such as is positively jet- 

 black, appear shades of yellow. Fair or golden hair is a 

 light yellow, red and auburn hair are deeper tones, more 

 intensely coloured, and all varieties of brown are darker 

 still. 



The word is also used for the colour of horses. All 

 the varieties of chestnut and bay are to the colour-blind 

 dark yellow, a yellow brown, the former of a lighter, the 

 latter of a darker shade. 



'EpvBpos. 



This is, I suppose, the most usual Greek word for red. 



Mr. Gladstone (N. 375) takes it to be the best approach 



to a true genuine colour-epithet, but at the same time he 



remarks how strange it is that Homer's idea even of red 



does not seem to be wholly distinct. 



The difficulty, however, vanishes if we suppose Homer 

 to have been in the position of the colour-blind, to whom, 

 as I have explained, the proper idea of red is unknown. 

 The word, according to Mr. Gladstone (N. 375, H. 460), 

 is applied to copper, nectar, wine, and blood, all which, 

 though they may differ in appearance to the normal-eyed, 

 present to the colour-blind only different modifications of 

 the yellow sensation. 



In regard to blood, the hue varies according to its con- 

 dition, arterial blood differing materially from venous 

 blood in its colour. I believe that normal-eyed people 

 hesitate to recognise any yellow element in it in any condi- 

 tion, but it is quite certain that when bright and freshly- 

 oxygenated, it presents a sensation of yellow to me ; and 

 this is consistent with the fact that its colour is said to be 

 chiefly due to the oxygenation of the iron it contams, 

 the peroxide of iron being to me very positively yellow. 

 I conceive it may be possible that in this, as in many 



« Continued from p. 679. 



