March II, 1 8 86] 



NATURE 



455 



that the vast region including the warm and moist parts of South 

 and Central America should be regarded as a single botanical 

 province, in which the same generic types are represented by 

 species of which a large proportion are endemic, and confined 

 to comparatively small areas. Along with these we find, in 

 various parts of the same region, a few forms so distinct as to 

 be ranked as separate genera, mostly represented by one, or 

 very few, species, and nearly allied to types of wide distribution. 

 He assumes that, in a broad sense, the most natural divisions of 

 the vegetation of the earth are wide areas of low country, over 

 which, with more or less modification, a limited number of 

 types have extended, with islands of high land, which are the 

 original homes of special types that form the characteristic 

 features of different regions. 



Zoological Society, March 2. — Dr. St. George Mivart, 

 F.R.S., Vice-President, in the chair.— Mr. J. G. Millais, 

 F.Z. S., exhibited an adult specimen of the Ivory Gull, shot: by 

 himself near Thurso, in December 18S5 : also a young example 

 of the same species, obtained in Scotland in 1879. — Mr. T. D. 

 A. Cockerell exhibited a living Slug of the genus Parmacella, 

 obtained at Tangier, and probably referable to P. I'tikiicioinesi. 

 — A communication was read from Prof. R. Collett, C.M.Z.S., 

 containing an account of a new Pediculate fish from the sea ofi" 

 Madeira, belonging to the family Ceratiida;, which the author 

 proposed to call Litiophryne liictfn: — Mr. P. L. Sclater read a 

 note on the external characters of the head of Rhinoceros simus 

 as compared with those of ]\. bicornis. — Mr. F. E. Beddard 

 read a note on the air-sacs of the Ca>;sowary. — A second paper 

 by Mr. Beddard treated of the syrinx and some other points in 

 the anatomy of certnin forms of Caprimulgidie. 



Entomological Society, March 3.— Mr. Robert McLachlan, 

 F.R.S., President, in the chair, — Mr. J. M. C.Johnston was 

 elected a Fellow, and Cavaliere Piero Bargagli, of Florence, 

 was elected a Foreign Member. — Mr. Pascoe exhibited a curious 

 larva, probably of a Piipilio, from Para ; and also a pupa-case of 

 Anosia plexippus {Daiiais nrchippiis), from the same locality. — 

 Mr. W. J. Williams exhibited, on behalf of Mr. C. Bartlett, 

 a gigantic hairy and spiny larva, perhajss allied to Gaslropacha, 

 from.- Madagascar. — Mr. C. O. Waterhouse exhibited Rutcla 

 riifipennis, Dorypliora haroldi, and some other (undescribed) 

 species of Coltoptera, from Colombia. — Mr. Billups exhibited a 

 specimen of Cholus /or/iesei, found alive in a horticultural sale- 

 room in London. — Mr. Eland-Shaw referred to the exhibition at 

 the last meeting of Tdlix aiistralis from New South Wales, 

 and called attention to the fact that the aquatic habits of certain 

 species of the genus Tdlix in India had been previously re- 

 corded. — Dr. Fritz Midler communicated a paper on fig insects 

 from Itajahy, South America ; and Prof. Meldola exhibited, on 

 behalf of Dr. Fritz Miiller, a number of specimens of the insects 

 described in the paper. — Mr. E. B. Poulton read further notes 

 upon lepidopterous Iar\'X and pupa?, including an account of 

 the loss of weight in the freshly formed pupa. 



Dublin 

 University Experimental Science Association, January 

 27. — Prof. Cathcart in the chair. — Prof. Fitzgerald showed his 

 new galvanometer. This instrument was constructed, and 

 exhibited in the Inventions Exhibition last year, by the 

 Cambridge Scientific Instrument Company. Its peculiarities 

 are (i) the arrangement by nhich the coils can be measured in 

 their place, which is an advantage when practical classes are 

 working, and should measure their instruments ; (2) the 

 arrangement by which the circle is read with a microscope by 

 reflection-mirrors attached to the magnet, when the instrument 

 is used either as a sine or tangent galvanometer; (3) an 

 arrangement by which a spot of light reads the tangents of de- 

 flection. The first advantage is secured by having the two pairs of 

 short and long coils wound in grooves closed in, outside, by a 

 glass plate through which they can be seen, and the external 

 and internal diameter of each layer of wire measured ; the 

 transverse diameter, by seeing through small holes left in the 

 ring that covers the coils outside. The reading is effected by 

 viewing a scale engraved on the inside of a horizontal ring sur- 

 rounding the needle by reflection in two right-angled prisms 

 attached to the needle which reflect opposite sides of the scale. 

 The corresponding lines in the two maps, which difler by 

 exactly iSo°, is the line at right angles to the line of intersection 

 of the reflecting planes of the prism. The exact position of that 

 .ine can be read by means of a micrometer in the ej'e-piece of 



the microscope. The horizontal graduated ring is attached 

 through the vertical axis on which the coils, &c., turn to the 

 base of the instrument, and so the same circle does for reading 

 when the instrument is used as a sine galvanometer. By means 

 of a small mirror attached to the needle at 45° to the line of 

 suspension, a spot of light can be reflected through the glass 

 side of the instrument to a scale, and then a uniform scale 

 represents the tangents of the deflections. — Mr. J. Joly, B.E., 

 gave an account of a method of finding the specific gravity of 

 small heavy bodies. The substance, whose specific gravity is 

 required, which may only be a few milligrammes in weight, is 

 melted into a small dish of paraffin of known specific gravity. 

 The paraffin and substance is then floated in a specific gravity 

 solution, and from the formula 



W 

 S = — 



the required specific gravity of the body can be obtained. In 

 the above equation Wh the weight of the solid, w.^ that of the 

 paraffin, lo', the sum of these weights ; s.^ is the specific gravity 

 of paraffin, .c, the specific gravity of paraffin and substance 

 together This method is extremely useful in dealing with 

 porous bodies, owing to the capability of paraffin, when in a 

 molten state, of entering the pores and expelling air. Mr. Joly 

 gave details of a number of experiments which show excellent 

 results. — The next paper was read by Mr. Gerald Stoney, on 

 the dynamics of bicycling. He described experiments made by 

 him, in conjunction with his father, Dr. G. Johnstone Stoney, 

 F. R. S., by which tlie energy required to propel a bicycle was 

 obtained. They found that it required, when the velocity was 

 9 miles per hour, about 5500 foot-pounds per minute, and that 

 it often rose higher than 10,000 foot-pounds per minute, which 

 was the highest the apparatus used was capable of recording. 

 Their results were higher than those of other experimenters on 

 the power a man can exert. This shows that the bicycle or tri- 

 cycle is probably the most economical way of using human 

 muscles. The experiments were made by attaching an indicator- 

 diagram-apparatus to the lever of the safety-bicycle, known as 

 the " Extraordinary," and also by observing the reduction in 

 speed due to friction, when the bicycle was running free. The 

 experiments also showed that the resistance varied almost as the 

 velocity, and that the pressure on the pedal was not constant, 

 but was at a maximum at the centre of the stroke. 



Paris 

 Academy of Sciences, March i. — M. Jurien de la 

 Graviere, President, in the chair. — Results of the application 

 of the new method for preventing rabies after the bite of a mad 

 dog, by M. Louis Pasteur. Since October 26, 1885, when his 

 process was first announced to the Academy, 350 patients of 

 all ages and both sexes have been treated with perfect success 

 in every case except one. The eminent biologist considers his 

 prophylactic method established, and expresses a hope that a 

 hospital may now be founded for the regular treatment of 

 patients by this process of inoculation. This suggestion met 

 with general approval, and a Commission was appointed to give 

 it effect, including the names of MM. Vulpiau, Marey, P. Bert, 

 Jurien de la Graviere, Bertrand, and De Freycinet. — Direct 

 formulas for calculating the momenta of flexion in continuous 

 girders of constant or variable section, by M. Maurice Levy. — 

 Note on the comparative results of direct astronouucal obser\'a- 

 tion with those obtained by MM. Henry's photographic process, 

 by M. Wolf. Discrepancies are pointed out between the photo- 

 graphs of the Pleiades and the author's observations of that 

 constellation in 1S74. He adds : " The chart of the heavens 

 now obtained by photography is different from that drawn from 

 direct observation, and it also differs from that which will be 

 obtained twenty years hence by the photography of the future, 

 whose processes will certainly be different from ours. The 

 human eye, on the contrary, is an organ which is always the 

 same ; consequently its observations are always capable of being 

 compared together. . . . Celestial photography must work 

 hand in hand with the observer's eye, which it can never replac" 

 — Reply to M. Lalanne's note of February 22, on the mechani- 

 cal effects of tornadoes, by M. Faye. M. Lalanne's facts are 

 not questioned, but they are shown to be perfectly in accordance 

 with M. Faye's well-known theory.- — Remarks on the various 

 theories of tornadoes, by M. Lecoq de Boi>.baudran. While 

 admitting the descending movement .as the general law, the 



