NATURE 



[May 12, 1898 



Photographic Action of Printer's Ink. 



In your issue dated April 28, I notice ^n article reporting 

 the Bakerian Lecture given by Dr. W. J. Russell. 



One paragraph states that printing ink at a distance will act 

 upon a photographic film. Is that the explanation of the 

 following curious circumstance? 



An Ilford ordinary plate, which I had kept in its box un- 

 opened for five years, was exposed recently upon a poorly- 

 lighted subject ; upon development I found, instead of my 

 subject, the matter of the advertisement which was upon the 

 outside wrapper. This came up strong and quickly, but nothing 

 was seen of the subject upon which the plate had been exposed 

 in the camera. 



The image was a positive, and the large type word " Ilford " 

 was very prominent. 



So it would appear that the sensitised plate had been acted 

 upon by the printer's ink, through the lid of the box and three 

 wrappers of paper, two of which were brown. 



W. Trueman Tucker. 



Parkside, Loughborough, May 8. 



A VERY interesting result. The picture no doubt arose from 

 the printer's ink, and it shows what great length of time will do. 

 The plate must have been face upwards. W. J. R. 



May 9. 



Electrical Impressions on Photographic Plates. 



Some simple variations of the inductoscript may be of 

 general interest. 



A photographic glass negative is placed on a plate, and a 

 f-inch induction coil is sparked for one or two minutes on the 

 outsides : a perfect positive with fine detail can be developed. 



If printed paper is so treated, a clear image of the reading is 

 made, white letters on a dark ground : a coin gives dark 

 letters. 



If the exposure to the spark is prolonged, an indistinct image 

 of the print, which is on the other side of the paper, will 

 also appear. 



More or less perfect images can be made, if ink or pencil 

 writing or a photographic print be put on the plate. When thin 

 paper is placed between a coin and a plate, a fair, but less 

 perfect, reproduction of the coin will be produced. 



It makes very little difference whether fast or slow plates are 

 employed. A. S. Bates. 



Winchester College. 



Bacteria on an Ancient Bronze Implement. 



A FEW days ago an ancient bronze implement was brought to 

 me showing small excrescences, the centres of rapid oxidisation, 

 which the owner told me had only very recently developed. 



On examining the material scraped off one of these ex- 

 crescences under the microscope with fairly high powers (a 

 \ inch and -f inch objective), it was found to be swarming with 

 bacteria, which seemed to be the cause of the rapid oxidisation. 

 I have not been able to trace any reference to bacteria inhabiting 

 a similar nidus, and I should be much obliged to any correspon- 

 dent who could direct me to the literature on the subject, and 

 inform me of the best way of sterilising the implement without 

 injury. Wm. Edward Nicholson. 



Lewes, May 3. 



THE ROYAL SOCIETY SELECTED 

 CANDIDA TES. 

 'T^HE following are the names and qualifications of the 

 -*■ fifteen candidates selected by the Council of the 

 Royal Society, to be recommended for election into the 

 Society this year : — 



Henry Frederick Baker, 

 M.A., Fellow and Lecturer of St. John's College, Cambridge ; 

 University Lecturer in Mathematics. Author of " A Treatise on 

 Abel's Theorem and the Allied Theory" (1897) ; and of the fol- 

 lowing papers, among others : — " Weierstrassian Formulae 

 applied to the Binary Quartic and Ternary Cubic" {Quart. 

 fourn. Math., vol. xxiv., 1889); "Gordon's Series in the 



NO. 1489, VOL. 58] 



Theory of Forms" {Messenger Math., vol. xix., 1889) '■> "The 

 Full System of Concomitants of Three Ternary Quadrics" 

 {Canib. Phil. Soc. Trans., vol. xv., 1889); "The Application 

 of Newton's Polygon to the Singular Points of Algebraic Func- 

 tions" {ibid., vol. XV., 1893) ; "OnEuler's (^-Function" {Proc. 

 Land. Math. Soc, vol. xxi., 1890) ; " Fundamental Systems for 

 Algebraic Functions" {ibid., vol. xxvi., 1895) ? "On Noether's 

 Fundamental Theorem" {Math. Annalen., vol. xlii., 1893); 

 "On a Geometrical Proof of Jacobi's I-Function Formula" 

 {ibid., vol. xliii., 1893); "On the Theory of Riemann's In- 

 tegrals" {ibid.,\o\. xlv., 1894) ; "The Practical Determination 

 of the Deficiency and Adjoint ^-Curves for a Riemann Surface " 

 {ibid., vol. xlv., 1894); " On a Certain Automorphic Function " 

 {Camb. Phil. Soc. Proc, vol. viii., 1895); "On the Hyper- 

 elliptic Sigma-Functions " {Amer. Journ. Math., vol. xx., 

 1897). 



Ernest William Brown, 

 Professor in Haverford College. Formerly Fellow of Christ's 

 College, Cambridge. Author of the following papers : — In the 

 American Journal of Mathematics— "■ Ovi the Part of the 

 Parallactic Inequalities in the Moon's Motion, which is a 

 Function of the Mean Motions of the Sun and Moon " (vol. xiv., 

 pp. 141-160, 1892); "The Elliptic InequaUties in the Lunar 

 Theory "(vol. xv., pp. 244-263,321-338,1893); "Investiga- 

 tions in the Lunar Theory" (vol. xvii., pp. 318-358, 1895). I" 

 the Monthly Notices Royal Astronomical Society — " On the De- 

 termination of a Certain Class of Inequalities in the Moon's 

 Motion" (vol. Hi. pp. 71-80, 1891) ; " Notes on Lunar Theory " 

 (vol. Hi. pp. 408-9, 1892; liv. p. 471, 1894; Iv. pp. 3-5, 

 1894); "Note on Hansen's Lunar and Planetary Theories" 

 (Ivi. pp. 52-3, 1895) ; " J^ote on Mr. Stone's paper, ' Ex- 

 pressions for the Elliptic Coordinates of a Moving Point to the 

 Seventh Order of Small Quantities,' " 1896. In the Proceedings 

 Cambridge Philosophical Society — " On the Part of the Paral- 

 lactic Class of Inequalities in the Moon's Motion which is a 

 Function of the Ratio of the Mean Motions of the Sun and 

 Moon" (vol. vii. pp. 220-1, 1891). Before the London 

 Mathematical Society, November 1896 — On "The Applica- 

 tion of Jacobi's Dynamical Method to the General Problem of 

 the Three Bodies"; "On Certain Properties of the Mean 

 Motions, and the Secular Accelerations of the Principal Argu- 

 ments used in the Lunar Theory." Author of " An Intro- 

 ductory Treatise on the Lunar Theory " (Cambridge University 

 Press, 1896, pp. vni.-292). 



Supplementary Certificate. — - " On the Mean Motions of the 

 Perigee and Node " ; " On the Theoretical Values of the Secular 

 Accelerations of the Lunar Theory" ; "Note on the Mean 

 Motions of the Perigee and Node," in the Monthly Notices 

 R. Astron. Soc, 1897; "Theory of the Moon, containing a 

 New Calculation of the Coordinates of the Moon in Terms of 

 the Time " (Part I. -IV. Me?noirs R. Astron. Soc, vol. Hu., 

 1897, PP- 39-116). 



Alexander Buchan, 



M.A., LL.D., F.R.S.E. Secretary, Scottish Meteorological 

 Society, from i860. Member of the Meteorological Council 

 from 1873. Author of the following contributions to Meteor- 

 ology : " Mean Atmospheric Pressure and Pievailing Winds of 

 the Globe and Handy Book of Meteorology," 1868 ; "Weather 

 and Health of London," jointly with Sir Arthur Mitchell, 

 1875 ; " Challenger Report on Atmospheric Circulation in 

 1889" ; " Challenger Report on Oceanic Circulation in 1895 " ; 

 " Specific Gravities and Oceanic Circulation in 1896 " ; 

 "Meteorology," in the " Encyclopaedia Britannica " ; Reports 

 on the Meteorology of Ben Nevis, &c. 



Sidney Frederic Harmer, 



M.A., Superintendent of the University Museum of Zoology, 

 and F ellow of King's College, Cambridge. Engaged for many 

 years in researches in Embryology and Comparative Anatomy. 

 Discoverer of important facts connected with the Anatomy of 

 Cephalodiscus, which largely assisted in fixing its systematic 

 position ; and of the occurrence of a process of extensive Em- 

 bryonic Fission in certain Polyzoa. Author of numerous papers 

 on zoological subjects, including the following: — "On the 

 Structure and Development of Loxosoma" {Quart. Journ. 

 Micros. Sci., vol. xxv., 1S85) ; " On the Life-history of Pedi- 

 cellina" {ibid., xxvii., 1887); "On the British Species of 

 Crisia" {ibid., xxxii., 1891) ; "On the Nature of the Excretory 



