May 8, 1879] 



NATURE 



39 



jittle, rather dingy, room in which, for well nigh thirty 

 rears, he has sat amidst blue-books, calendars, mineralo- 

 "gical specimens, and a rather orderly chaos of miscel- 

 laneous objects. They will think with sadness of the 

 rupture of these old associations, and will follow to the 

 grave with deep respect and sincere regret the old friend 

 who has been so suddenly and unexpectedly removed from 

 their midst. 



WILLIAM GEORGE VALENTIN 



IT is with much regret that we record the untimely and 

 sudden death on the ist inst. from apoplexy of Mr. 

 William George Valentin. He was born in Neuenburg, 

 in the Black Forest, on May 16, 1829. He came to 

 England in 1855, and, in the early days of the Royal 

 College of Chemistry, studied under Dr. Hofmann, who 

 esteemed him greatly, and, recognising his ability, made 

 him senior assistant in the laboratory, a position which 

 he retained at the Science Schools, South Kensington, 

 under Dr. Frankland. He held for some years the office 

 of gas examiner to the Great Western Gas Company, 

 and at the time of his death was chemical adviser to the 

 Trinity House. 



His chemical text-books are deservedly popular ; and 

 within the last few days he corrected the final proofs of a 

 new work which is therefore nearly ready for publication. 



Mr. Valentin was a successful and painstaking teacher, 

 and the fact that so many of the well-known chemists of 

 this generation have received their early training from 

 him, sufficiently indicates the value of his work ; it would 

 be difficult, indeed, to find one to whom the younger 

 chemists of the present day are more indebted. 



Within the last few weeks a few of his old friends and 

 students of the Royal School of Mines had intended to 

 present him with a testimonial ; the efforts of the 

 committee formed for this purpose will now be continued 

 for the benefit of his widow and family. 



ELECTRIC LIGHTING 

 "V^E need not insist on the extreme importance and 



* • interest of the exhibition which was opened last 

 night at the Albert Hall, and for which extensive prepara- 

 tions have been making for some time. The public mind 

 both in this country and abroad has been recently much 

 agitated on the question of electric lighting, and, as 

 might be expected, people are much confused among the 

 many systems which have been brought forward, and 

 even those who know something of the subject must find 

 it difficult to make up their minds. Hence the import- 

 ance of bringing together the various systems of electric 

 lighting in such a way as to make comparison possible. 

 It must, moreover, have an important educational influ- 

 ence upon the general public, helping somewhat to give 

 them a truer idea of what physical science is, and what 

 it is capable of doing for the good of mankind. The 

 exhibition was opened last night by an able and interest- 

 ing lecture by Mr. W. H. Preece, the chair being occupied 

 by the Prince of Wales. 



The machines to be exhibited are not only those which 

 have been recently attracting attention, but also older 

 ones, which will exhibit in an impressive manner the 

 history of the development, of electric lighting. Thus 

 there are in the arena of the Albert Hall specimens 

 of Mr. Holmes's original magneto-electric machine, and 

 of the Alliance Company's magneto-electric machine, 

 lent by Trinity House, as well as the Siemens dynamo 

 machine and the Gramme machine, now so much in use 

 for generating electricity for lighting and other purposes. 

 There are aho varieties of the Gramme and Siemens ma- 

 chines, differing from each otlier more in minute detail 

 than in general principle. 



The Jablochkoff and the Lontin systems are also 

 strongly represented. From the centre of the dome 



depend five large lamps of the Siemens pattern, round 

 the upper corridor are ranged the Jablochkoff lamps 

 exhibited by the Soci^td Gdndrale d' Electricity, and 

 around the arena stand handsome specimens of the 

 Lontin lamp, mounted on tastefully-designed posts. 

 The Wilde lamp will also be strongly represented. This 

 may be briefly described as the Jablochkoff candle with 

 the central non-conducting substance left out. In addi- 

 tion to a powerful Gramme machine, the British Electric 

 Light Company exhibit several lamps, notably the Serrin, 

 hardly yet surpassed in some pomts of excellence, the 

 Werdermann, Reynier, Higgins, and Rapieff lights, and 

 it is stated that the Anglo-American Electric Light 

 Company will exhibit the Wallace and the Iridium In- 

 candescent fights, the last-named of which is of much the 

 same kind as that employed by Mr. Edison. The distin- 

 guishing characteristics of these various lights were 

 explained by Mr. W. H. Preece, and the exhibition, 

 which will remain open to the public for the remainder of 

 the week, promises to be by far the most attractive 

 display of scientific apparatus made for some considerable 

 time past. 



It may not be inappropriate to give here a short account 

 of a new form of electric lighting, which, it would seem, 

 will not be represented at the exhibition now oj;)ened at 

 the Albert Hall. 



At last week's meeting of the Paris Academy, M. 

 Jamin presented a model of an electric light for 

 which he claims the greatest possible simplicity. The 

 two carbons are kept parallel by two insulated copper 

 tubes, separated by an interval of two or three milli- 

 meters, in which they slide by friction, and which serve 

 at once to direct them and to guide the current. They 

 are surrounded by a directing circuit composed of five or 

 six spirals coiled on a thin rectangular frame '\o m. long 

 and •15 m. broad. This circuit, traversed by the same 

 current as the carbons, and in the same direction, guides 

 and fixes the electric arc at the extremity of the points. 

 The lighting is effected automatically. For this purpose, 

 the two extremities of the carbons are surrounded by a thin 

 caoutchouc band which keeps them close together. Between 

 them, a little above, a small fragment of iron wire is in- 

 troduced, which keeps them in close communication by a 

 single point. As soon as the circuit is closed, the current 

 traverses this wire, makes it red-hot, and melts the caout- 

 chouc ; the two carbons, thus freed, separate, and the arc 

 is established with a sort of explosion. Carbons of any 

 size may be employed, up to 8 mm. diameter. At this 

 limit the waste scarcely exceeds "08 m. per hour. By a 

 proper arrangement the points may be maintained in 

 their initial position. The apparatus may be suspended 

 either with the points upwards or directed towards the 

 ground. For several reasons, which Mr. Jamin states, 

 the latter position is preferable. With its points down- 

 wards, then, M. Jamin claims for his light the following 

 advantages r — i. That of simplicity, since it requires no 

 mechanism and no preliminary preparation ; all is reduced 

 to a support and to carbons ; (2) that of mechanical 

 economy, since it succeeds in almost doubling the number 

 of lights ; (3) increase of illumination, since each of the 

 new lights is nearly twice as powerful as the old ; (4) quality 

 of light, which is more white; (5) a more advantageous 

 arrangement of the poles, which throw their greatest 

 amount of light downwards, where it is required, instead 

 of losing it towards the sky, where it is useless ; (6) 

 finally, economy of the combustibla material, since the 

 waste is less in proportion to the size of the carbons. 



NOTES 



We greatly regret to announce the death at Rome, on April 14^ 

 of Prof. Paolo Volpicelli, the well known Italian electrician. 

 We hope to be able to give details of his life and work in an 

 early number. 



