192 



NATURE 



[June 21, 1900 



St. Louis. 

 Academy of Science, May 23.— A paper by Dr. Adolf Alt, 

 entitled " Original contributions concerning the glandular struc- 

 tures appertaining to the human eye and its appendages," was 

 presented by title.— Dr. M. A. Goldstein read a paper on the 

 physiology of voice production, in which he discussed three 

 essential factors in the production of voice— the motor force, the 

 organ of sound, and the resonators.— Prof. F. E. Nipher read a 

 short communication on the zero photographic plate, to which 

 reference was made at the meeting of May 7 (see pp. 62, 159). 

 The zero plate is one upon which a photographic image has been 

 made, but which will develop no image in a bath placed in light 

 of given candle power, at a distance of one metre from the 

 source. For example, if the developing bath is twenty centi- 

 metres from a sixteen candle lamp, a Cramer isochromatic plate, 

 such as is called "instantaneous," held for ninety seconds at a 

 "distance of one metre from the lamp, will be a zero plate. With 

 an opaque stencil over the plate when placed in a printing frame 

 during the exposure, there will develop a positive of holes 

 through the stencil, if the exposure is longer, and a negative 

 if the exposure is shorter. If a fresh plate is exposed in our 

 camera with full opening to a brilliantly lighted street scene for 

 one minute, it will develop as a positive in that same bath. This 

 time can be somewhat reduced, but the least time needed has not 

 yet been determined. It is evident that part of this minute is 

 used in producing a zero plate. It is furthermore clear that 

 different parts of the plate will arrive at the zero condition at 

 different times. The exposure may be arrested at a time when 

 -the strongly lighted white background of a sign-board will develop 

 white as a positive, and when the black letters will also show 

 white as a negative. It has been found that when a plate is 

 uniformly exposed over its whole surface to the extent that 

 nothing would have developed had it been covered by a sten- 

 cil, this plate may then be placed in a camera and exposed in 

 the ordinary way, and a perfect positive will develop in the bath 

 to which it has been adapted. This preliminary spoiling of the 

 plate for developing a negative is a very advantageous prepara- 

 tion for taking a positive. It shortens the time of exposure, and 

 ■ensures that a positive shall be obtained over all parts of the 

 plate. It is not yet known how short the camera exposure may 

 be made, but the present indications are that they will be as 

 short as those now made in the taking of negative pictures. It 

 is currently believed by photographers that in a positive plate 

 the object has " printed its picture " upon the plate. This ap- 

 pears to be a misconception of the process. It is true that in an 

 exposure of long duration an image shows on the plate before it 

 is placed in the bath. But this image is blackest where the light 

 has acted most. It is a negative. This picture disappears in the 

 developing bath when illuminated. The plate becomes perfectly 

 clean. The positive picture then develops exactly as a negative 

 would under ordinary conditions.— Mr. J. B. S. Norton 

 presented some notes on the flora of the south-western United 

 States 



DIARY OF SOCIETIES. 



THURSDAY, June 21. 



Royal Society, at 4.30. — On the Effects of Changes of Temperature on 

 the Elasticities and Internal Viscosity of Metal Wires : Prof. A. Gray, 

 F.R.S., V. J. Blyth, and J. S. Dunlop.— On the Connection between the 

 Electrical Properties and the Chemical Composition of Different Kinds of 

 Glass, Part II.: Prof. A. Gray, F.R.S., and Prof. J. J. Dobbie.— On 

 the Change of Resistance in Iron produced by Magnetisation : Prof A. 

 Gr.ay, F.R.S., and Prof. E. T. Jones. — Underground Temperature at 

 Oxford in the Year 1899, as determined by Five Platinum Resistance 

 Thermometers: Dr. A. A. Rambaut, F.R.S.— On the Kinetic Accumu- 

 lation of Stress, illustrated by the Theory of Impulsive Torsion : Prof. 

 K. Pearson, F.R.S. — Lines of Induction in a Magnetic Field : Prof. 

 Hele-Shaw, F.R.S. , and A. Hay.— On the Spectroscopic Examination of 

 Colour produced by Simultaneous Contrast: G. J. Burch, F.R.S. — An 

 Experimental Investigation into the Flow of Marble : Dr. F. D. Adams 

 and Dr. J. T. Nicolson. — A Criticism of the Young-Helmholtz Theory of 

 Colour Perception : Dr. F. W. Edridge-Green.— And other Papers. 



LiNNEAN Society, at 8. — On some Scandinavian Crustacea: Dr. A. G. 

 Ohlin. — The Subterranean Amphipoda of the British Islands : Chas. 

 Chilton. — On certain Glands of Australian Earthworms : Miss Sweet. — 

 Notes on Najas : Dr. A. B. Rendle. 



Zoological Society, at 4.30. — The Gigantic Sloths of Patagonia : Prof. 

 E. Ray Lankester, F.R.S. 



Anatomical Society (Owens College, Manchester), at 10.30. — Lantern 

 Demonstration on the Comparative Anatomy and Histology of the True 

 Caecal Apex — the Appendix Vermiformis : Dr. R. J. Berry. — Lantern De- 

 monstration of some Surface Markings of the Calvaria, and their Signi- 

 ficance : Prof. Dixon. — Lantern Demonstration of Microphotographs of 

 the Maturation Stages in the Ovum of Echinus : Dr. T. H. Bryce. — 



NO. 1599, VOL. 62] 



Some Points in the Anatomy of the Digestive System : Prof. Birming- 

 ham. — {a) Two Cases of Absent Vermiform Appendix ; {b) A Specimen 

 showing Direct Continuity between the Long External Lateral Liga- 

 ment of the Knee-joint and the Peroneus Longus Muscle ; {c) A Super- 

 numerary Bone in the Carpus connected with the Trapezium : Prof. 

 Fawcett. — A Note on the Genit.al Apparatus of the Jerboa: Dr. 

 Armour. 

 Chemical Society, at 8.— Ballot for the Election of Fellows.— Notes on 

 the Chemistry of Chlorophyll : Dr. L. Marchlewski and C. A. Schunck. 

 —Researches on Morphine, I.: Dr. S. B Schryver and F. H. Lees.— 

 A New Series of Pentamethylene Derivatives, I. : Prof W. H. Perkin, 

 jun., F.R.S , Dr. J F. Thorpe, and C. W. Walker.— Experiments on 

 the Synthesis of Camphoric Acid. III. The Action of Sodium and 

 Methyl Iodide on Ethvl-dimethyl-butanetricarboxylate : Prof. W. H. 

 Perkin, jun., F.R.S., and Dr. J. F. Thorpe.— On the Oxime of Mesox- 

 amide and some Allied Compounds : Miss M. A Whiteley. — The Oxy- 

 phenoxy- and Pbenylenenxy-acetic Acids : W. Carter and Dr. W. T. 

 Lawrence.— (i) The Condensation of Ethyl a-Bromo-isobutyrate with 

 Ethyl Malonates and P^thyl Cyanacetates : a-Methyl-a'-isobutylglutaric 

 Acid; (2) Methylisoamylsuccinic Acid, II.: Dr. W. T. Lawrence. 



FRIDAY, June 22. 



Physical Sociktv, at 5 —Notes on Gas Thermometry: Dr. P. 

 Chappuis. — A Comparison of Impure Platinum Thermometers : H. M. 

 Tory.— On the Law of Cailletet and Mathias and the Critical Density : 

 Prof. J. Young, F.R.S. 



Anatomical Society (Owens College, Manchester), at 10.30.— Note on 

 the Configuration of the Heart in a Man and some other Mammalian 

 Groups: Dr. C. J. Patten.— On the Arrangement of the Pelvic Fasciae 

 and their Relationship to the Levator Ani : Dr. Peter Thompson.— (a) A 

 Preliminary Note on the Development of the Sternum ; (b) Specimens 

 of Diaphragmatic Hernia and of a Leit Inferior Vena Cava : Prof. 

 Paterson— Preparations and Lantern Slides illustrating : (a) The 

 Anatomy of the Subclavian and Axillary Arteries ; ih) The Position and 

 Relations of the Eustachian Tubes : (c) Stereo.scopic Views of Anatomical 

 Preparations : Dr. Arthur Robinson.— A Series of Microscopical Pre- 

 parations illustratine the Development of the Posterior End of the 

 Aorta : Prof. Young and Dr. Arthur Robinson.— Demonstration of a 

 Series of Preparations of the Posterior End of the Adult Aorta : Prof. 

 Young. 



MONDAY, June 25. 



Royal Geographical Society, at 8.30.— Results of the Sir George 

 Newnes Antarctic Expedition : C. E. Borchgrevink. 



TUESDAY, June 26. 

 Royal Photographic Society, at 8.— The Selection of Lenses with 

 regard to Photographic Perspective: J. H. Agar Baugh.— How to ascer- 

 tain the Conjugates of a Lens without Calculation : Rev. F. C. Lambert. 



CONTENTS. PAGE 



The Reminiscences of a Veteran of Science. By 



E. A. M 169 



Differential Equations. By G. B. M 170 



Our Book Shelf:— 



Macnamara : "Origin and Character of the British 



People" 172 



Salisbury and Atwood : "The Geography of the 

 Region about Devil's Lake and the Dalles of the 



Wisconsin" 172 



Sack :'" Monistische Gottes- und Weltanschauung." — 



H. W. B 172 



Lyster: " First Stage Hygiene " I73 



Letters to the Editor: — 



Measurements in Schools. Collateral Heredity.— 



Prof. Karl Pearson, F.R.S 173 



The Perseid Meteoric Shower.— W. F. Denning . 173 

 Variations in Plants of the Herb Paris.— Miss L. 



Eleanor Jex-Blake ; E. F. • • • I74 



Quaternion Methods applied to Dynamics. — W. G. 



Barnett I74 



Plant Hybrids. {Illustrated.) By Wilfred Mark 



Webb 174 



Our Northern Birds. {Illustrated.) By R. L. ... 177 



Notes 178 



Our Astronomical Column:— 



French Observations of the Total Eclipse of the Sun 183 



The Total EcHpse Observed at Sea 183 



New Variable Star in Cepheus 183 



Ephemeris of Eros 184 



Howe's Photographic Observation of Eros 184 



A Modern University. 1 184 



The Steadying of Ships. ( With Diagrams. ) By Prof. 



G. H. Bryan, F.R.S 186 



The "Orthostigmat " Lens 188 



University and Educational Intelligence 188 



Scientific Serial 189 



Societies and Academies 189 



Diary of Societies 192 



