512 



NATURE 



{April 2^, 1878 



obtained, and by bringing the iron keeper near to, or 

 even into gentle contact with the magnet, every grade and 

 rate of simple vibration could be reproduced, as the 

 present writer is able to testify. 



With this instrument Reis obtained better results and 

 even transmitted imperfect articulation. Legat speaks of 

 single words in reading and speaking being indistinctly 

 heard ; but any sudden modulation of the voice as in 

 surprise, interrogation, &c., was clearly reproduced. Still 

 more definite is the following statement, occurring in an 

 article on Reis's improved telephone in No. 15 of Bottger's 

 Polytechnisches Notizblatt (1863): — "The experimenters 

 could even communicate to each other words, only such, 

 however, as they had already heard frequently." In con- 

 firmation of this the present writer has received a letter 

 from Dr. Messel, a name well known to chemists, who 

 was a former pupil of Philip Reis and an eye-witness of 

 his early experiments. Dr. Messel states — " There is not 

 the shadow of a doubt about Reis having achieved im- 

 perfect articulation ; I personally recollect this very dis- 

 tinctly and could find you many others who were witnesses 

 of the same fact." ^ 



As an interesting sequel to this historical note it should 

 be mentioned that in 1865 Mr. S. Yeates, the skilful 

 instrument maker of Dublin, introduced some modifica- 

 tions in one of Reis's instruments he had purchased, of 

 the usual early form, which enabled him to obtain the dis- 

 tinct articulation of several words. The modifications 

 were twofold : (i) the knitting needle receiver was re- 

 placed by an electro-magnet and movable keeper, as Reis 

 l^ad already done, though unknown to Mr. Yeates (see 

 Fig. 5) ; and (2) a drop of very slightly acidulated water 



Fig. s — Yeates's receiver for Reis's telephone. Upon the sounding box b 

 an electro-magnet cc is supported by the brass pillar seen behind A 

 light iron keeper k is fastened at one end by a steel spring to a wooden 

 bridge, which can be raised or lowered by the screw d, so that the 

 keeper can be brought almost into contact with the electro-magnet The 

 circuit is completed by the binding screws j s. 



was placed between the contact pin and the metal disc on 

 the membrane. The intermittent character of the current 

 was thus abolished, and a very near approach made to 

 the true principle of an articulating telephone, namely, 

 the employment of a continuous current of varying 

 strength. This instrument was shown in November, 

 1865, at a meeting of the Dublin Philosophical Society, 

 and some members of that society who were then present 

 have testified to their remembrance of the fact that several 

 words were transmitted fairly well. It is to be regretted 

 that at the time Mr. Yeates did not pursue the matter 

 further, nor give a wider publication to the success he 

 obtained. 



But between the best of the results obtained by Reis 

 and others in the direction of articulation, and the splen- 

 did achievements of Prof. Graham Bell, there is unques- 

 tionably a very wide step. In the sensitive and beautiful 

 instrument discovered by Prof. Bell, the voice of the 

 speaker generates thrills of magneto-electricity, which, 

 being strictly proportional to the sonorous vibrations, 

 reproduces the voice and its expression in the receiver in 

 a fairy-like far-away whisper. Nevertheless it must be 

 borne in mind that it is unlikely the telephone of the 

 future will employ the voice to generate the driving 

 power, but only to modulate the flow of a current ob- 



' My best thanks are due to Dr. Messel for much information concerning 

 Reis and lor a reference to his papeis in the journals alluded to. 



tained by coarser means. It is in this direction that Reis 

 worked, and though his method was faulty in the employ- 

 ment of an intermittent current, the same cannot be said 

 of the arrangements adopted by Mr. Edison, of New 

 Jersey. And inasmuch as Mr. Edison has already dis- 

 covered and brought to a practical issue such remarkable 

 additions to our knowledge as quadruplex telegraphy, the 

 electro-motograph, and the phonograph, we have, in these 

 achievements, the earnest of success to those excellent 

 telephonic investigations wherein Mr. Edison has already 

 won an enduring fame. W. F. Barrett 



P.S. — Since writing the foregoing article, the publication 

 of which has been for some time delayed owing to the 

 crowded state of the columns of Nature^ my attention 

 has been drawn to a claim made by Mr. John Cammack, 

 to be the first inventor of the electric telephone. From 

 this it would appear that in the early part of i860 Mr. 

 Cammack made and exhibited an electric telephone, 

 whilst a student in the Royal School of Medicine, 

 Manchester. A photographic copy of the original 

 drawing of the instrument has reached me, and so far 

 as this goes it embraces not only the intermittent current 

 used by Reis, but the principle of the continuous current 

 of varying strength employed by Bell and Edison. In 

 fact, if Mr. Cammack can furnish historical proof, the 

 arrangement shown in his drawing, with its explanatory 

 note, is identically the same as the method, long after 

 independently invented and patented by Prof. Graham 

 BelU W. F. B. 



ACTION OF LIGHT ON A SELENIUM 

 {GALVANIC) ELEMENT 



IN the course of a series of experiments on the electri- 

 cal behaviour of selenium, undertaken with a view to 

 remove, if possible, the difficulties in the way of con- 

 structing constant resistances of this material, I have had 

 occasion recently to investigate the effects of surface ten- 

 sion due to light. 



I find that the action of light on crystalline selenium 

 (annealed at 200° C.) is much more striking when the 

 selenium forms one element of a galvanic couple than 

 when it acts as a resistance. 



The most convenient arrangement which I have found 

 for observing this, is to make up a couple consisting of (i) 

 a plate of selenium hanging suspended by means of a 

 platinum wire, and (2) a strip of platinum foil, in distilled 

 water. The potentials of the two poles are not very 

 different, and any change in the electro-positiveness of 

 the selenium is at once very apparent. 



The first selenium-platinum element which I constructed 

 behaved as follows : — 



In the dark the element gave a steady electromotive 

 force of about o'l volt, the selenium "b^vixg positive to the 

 platinum. On admitting daylight to the selenium plate 

 it instantly became electro-negative to the platinum, show- 

 ing an electromotive force of 0-05 volt in that direction. 

 That is to say the selenium had become 0-15 volt more 

 electro-negative by the action of the light than it was 

 in the dark. 



I Perhaps the word "claim" is too strong, as I observe Mr. Cammack 

 speaks very modestly of the idea he so early sketched out. Such ideas are 

 of course valueless in a practical sense, unless brought to the test of experi- 

 ment, and this Mr. Cammack seems only partly to have done ; this too is 

 just where Prof. Bell succeeded ; by his persistent experiments overcoming 

 all obstacles and affording by the way a striking illustration that facts may 

 after all upset the strongest ci. priori conclusions. In connection with this 

 remark the following passage from the last edition of a well-known work on 

 Mental Physiology (p. 632), is not without interest:—" Everyone who accepts 

 as facts, merely on the evidence of his senses, or on the testimony of others 

 who partake of his own beliefs, what Common Sense [with capitals] tells 

 him to be much more probably the fiction of his own imagination— even 

 though confirmed by the testimony of hundreds affected with the same 

 epidemic delusion— must be regarded as the subject of a ' diluted insanity.' " 

 Yet Baron Munchausen's trumpet has been outdone by the phonograph : the 

 "fiction of imagination" by a fact "confirmed by the testimony of 

 hundreds." However as these latter have " merely the evidence of their 

 senses to offer," we presume they are all the victims of " a diluted insanity," 

 if the reasoning of the eminent author be accepted. 



