April i 6, [885 



NA TURE 



57i 



other, the nd upon 



In order that these 



dy 



four wheels may not similarly work with any other wheel, it is 



: diaphragms dividing the cube into six cells, 



each a pyramid standing on a face of the cube. They must be 



hat liquid may not be able to pass from one cell to 



pother through the diaphragm or beside the paddle-wheels ; to 



effect this the floats on the paddle-wheels would have to be 



,vn while passing the diaphragms. Thus the energy 



ion of such a medium would depend upon 



l d l - *2Y+('!i - #V+ (*l - - ? V 



\dy dz) \dz dx) \dx dy) 



And Maxwell has shown that this is also true for the ether. The 



he cubes should be filled up with diaphrag 

 which the paddles should pump liquid, and whose elasticity 

 should be the means of storing electrostatic energy in the 

 medium. The most complicated results follow from supposing 

 'he faces of the cubes of which the medium is constructed to 

 ent elasticities. Such a structure represents a crystall- 

 ine medium, and vibrations would be propagated in it according 

 to laws the same as those regulating the transmission of light in 

 crystalline media. If the cubes were twisted, the structure 

 would be like that of quartz or other substances rotating the 

 plane of polarisation. To represent magnetic rotation of the 

 plane of polarisation it would be necessary to introduce some 

 u connecting the ether with matter. The auth r, in 

 . insisted upon a view which regards the vibrations 

 constituting light to be of the nature of alterations of structure, 

 of displacements executed in a medium possi 



of an elastic jelly. — At the clo e of the meeting the 

 Follow ing instruments were exhibited and described in a conver- 

 sational manner by their makers : a chrono-baromcter and a 

 chrono-thermometer by Mr. Stanley. These instruments con- 

 sisted of clocks regulated by pendulums formed in the first 

 instrument of a mercurial barometer, and in the second of a 

 uometer inclosed in a hermetically-sealed air-chamber, 

 the inclosed barometer thus acting as an air-thermometer. In- 

 crease of pressure in the one case, and of temperature in the 

 other, causes the mercury to rise, and thus accelerates the pen- 

 dulum. By the gain or loss of time the mean pressure or tem- 

 perature can be calculated for any period. — A heliostat and a 

 galvanometer, by Mr. Conrad W. Cooke. The galvanometer 

 is intended to show the internal current in a cell. The battery 

 plate- are in two cells connected by four glass tubes in multiple 

 arc coiled around an astatic needle. The glass work is by Mr. 

 Gimingham. — A spherometer, by Mr. Hilger, was made of 

 aluminium, and combined lightness with rigidity. By an 

 electrical contact the maker asserted that measurements could be 

 made to one-millionth part of an inch. — Col. Malcolm exhibited a 

 spectroscope and a binocular field-glass in which the two eye- 

 ere separately adjustable ; and Dr. Watts exhibited a 

 simple modification of a quadrant electrometer. 



Royal Microscopical Society, March II. — Rev. Dr. Dall- 

 I U.S., President, in the chair. — Mr. Crisp exhibited 

 Wrnkel's class microscope with movable stage, Tolle's clinical 

 ipe, Seibert's portable microscope, and Swift's micro- 

 scope for examination of skin of sheep having a very long work- 

 ing distance, Griffiths' and Bertrand's objective adapters and a 

 new form of " finder." — Mr. II. G. Madan exhibited some new 

 kind- of glass, having found that a combination of ordinary blue 

 ith a peculiar bluish-green glass, known as " signal-green" 

 was much more convenient than the usual glass cell filled 

 with olution of cuprammonium sulphate. — Mr. Baker exhibited 

 some ol I 1 in book-form for placing on a shelf with 



books, tlu objects then lying flat.— Dr. C. v. Zenger's letter was 

 read describing a new mounting medium consisting of tribromide 

 enic in bisulphide of carbon, and giving a refractive index 

 in 1-6696 to 17082. An improved slide for viewing the 

 object on both sides was also described. — Mr. C. H. Hughes's 

 description was read of a stage for use with high powers to 

 prevent the decentring of the condenser, especially when used 

 with immersion contact. Vertical, horizontal, and oblique 

 n ins are given to the slide, while the stage remains station- 

 11 can be rotated. — Mr. E. M. Nelson exhibited a drawing 

 of comma bacillus showing the flagella. — Mr. J. Mayall, jun., 

 described the original ruling machine of the late Herr F. A. 

 Nobert, which was exhibited to the meeting. The foundation 

 of the machine was a dividing engine calculated to produce 

 parallel divisions far finer than could be marked by any ruling 

 point yet discovered. The division-plate had twenty circles of 



and these were supplemented by extremely fine gradu- 

 in two bands of silver imbedded near the edge, which 

 were viewed by means of two compound microscopes, each 

 provided with eyepiece screw micrometers of special construc- 

 tion. The movement of rotation was effected by a fine tangent 

 screw acting on a worm on the vertical edge of the division- 

 plate. The method employed by Herr Nobert for obtaining the 

 minute divisions of his test-plates (ranging from i-ioooth to 

 l-20,oooth of a Paris line) was to convert the radius of the 

 division-plate into a lever to move the glass plate on which the 

 rulings were made at right angles to the motion of the ruling 

 point. For this purpose he attached to the centre of the 

 rotating division-plate a bent arm, on which slid a bar of silver, 

 having at one end a finely-polished steel point which could be 

 adjusted by a scale and vernier so as to project more or less 

 beyond the centre of the division-plate or axis of rotation. The 

 radius of the division-plate thus became the long arm of the 

 lever, whilst the radius of the projection of the polished steel 

 point beyond the axis of rotation formed the short arm, the 

 centre of the division-plate being the fulcrum. The motion cf 

 the short arm of the lever was communicated by contact with 

 an agate plate to a polished steel cylinder adjusted to slide at 

 right angles to the movement of the ruling point in V-shaped 

 bearings of agate. The steel cylinder carried a circular metal 

 table, on which the glass plate to be ruled was fixed by wax and 

 clamps. The arrangement for carrying the diamond point was, 

 he believed, wholly designed by Herr Nobert, and was a most 

 ingenious combination of mechanism. — Mr. Mayall referred 

 briefly to the preparation of the glass plates for the rulings, which, 

 he said, were of specially " mild " composition. It was abun- 

 dantly proved by Herr Nobert's work that the perfection of the 

 mechanical part of the dividing-engine was not the only difficulty 

 which he had understood, and conquered. There was a still 

 greater dfficulty which he had understood, and in which he had 

 met with a success that gave him pre-eminence in this department 

 of micro-physics, and that was the preparation of the diamond 

 ruling-points. The description of these was deferred until the next 

 meeting. — Mr. C. Beck exhibited a modification of the "com- 

 plete " lamp fitted with a shallow glass reservoir instead of the 

 original one of metal, also a vertical illuminator with a new 

 form of diaphragm. — Dr. Van Heurck's note was received, send- 

 ing a copy of Prof. Abbe's opinion on the photographs of the 

 "beads" of A. pellucida, in which he stated that he had no 

 reason to doubt the reality of the beads. — Dr. J. D. Cox's note 

 was read as to actinic and visual foci. — Mr. F. Kitton's remarks 

 in commendation of balsam of Tolu for mounting were read.— 

 Dr. Ord exhibited and described some objects illustrating the 

 erosion of the surface of glass when exposed to the action of 

 carbmate of lime and a colloid.— Mr. J. W. Stephenson read 

 his paper, on a new catodioptric illuminator, having an aperture 

 exceeding that of any existing objective, or equal to 1-644 

 N.A. in flint glass, and 1-512 N.A. in crown glass.— Mr. 

 Cheshire and Mr. E. Chayne's paper on the pathogenic history 

 of a new bacillus (B. alvei) was then read, in which it was 

 shown that the disease attacking bees, and known as "foul 

 brood," was due to a bacillus. They had also discovered that 

 the disease yielded readily to treatment which consisted in feed- 

 ing the larva; with a syrup containing 1-600 per cent, of phenol. 

 A detailed explanation was given of the methods adopted in 

 tracing out the life-history of the bacillus, and a series of tubes 

 and bottles in which its propagation had been carried on were 

 exhibited.— Mr. Fowke read a paper on the first discovery of the 

 comma bacillus of cholera. He showed that the bacillus was 

 known and recognised thirty-five years ago by two Englishmen, 

 Messrs. Brittain and Swayne. It was pointed out that 11 was by 

 the breaking up of the rings discovered by original observers 

 that the so-called " comma" bacilli were formed.— Sixteen new 

 Fellows were proposed and elected. 



Manchester 

 Literary and Philosophical Society, February 10.— Prof. 

 W. C. Williamson, LL.D., F.R.S., President, in the chair.— 

 On some undescribed tracks of invertebrate animals from the 

 Carboniferous rocks, and on some inorganic phenomena, simu- 

 lating plant remains, produced on tidal shores, by Prof. W. C. 

 Williamson, LL.D., F.R.S., President. Prof. Williamsons 

 memoir first contained descriptions and figures of a new form of 

 Chrossocorda, which he named C. tuberculata, from the Yore- 

 dale rocks of Stonyhurst, in Lancashire, which genus has 

 hitherto been found only in Palaeozoic rocks of much older age 

 than the Yoredale beds. Reciting the views of Schimper and 



