April 2,0^ iZt^I 



NATURE 



503 



trating Savart's observations on the action of sound on 

 a jet of water. Dr. J. H. Gladstone exhibited some pho- 

 tographs of fluorescent substances. Bottles containing 

 fluorescent liquids, such as ;esculin or quinine di-sulphate, 

 appear in the photographs nearly as black as a bottle 

 filled with ink ; similarly, labels written with such liquids, 

 although the characters are ordinarily invisible to the 

 eye, show up their designs when photographed. In this 

 room were to be seen also photographs of the Naples 

 Aquarium, exhibited by Mr. \V. A. Lloyd, and one of Dr. 

 Dohrn's Zoological Station at Naples, lent by Mr. Dar- 

 win ; likewise some lithographed plates of recent Forami- 

 nifera from the Abrolhos Bank, exhibited by Profs. W. 

 K. Parker and Rupert Jones. Mr. J. Norman Lockyer 

 e.'chibited a series of photographs of metallic and solar 

 spectra enlarged by Messrs. Negretti and Zambra from 

 photographs taken by his new method of comparing 

 spectra by means of a perforated shutter sliding in front 

 of the slit of the spectroscope. In this room the new 

 sextant devised by Capt. J. E. Davis was exhibited. 

 This instrument, which will be found particularly useful 

 in night observations, permits the taking of a series of 

 observations without reading off each observation ; this 

 being accomplished by the adaptation of a micrometer 

 movement to the tangent- screw, and the application of 

 indicators to the arc of the instrument. Mr. Alfred Tribe 

 here exhibited some specimens of metals (palladium, 

 copper, &c.) which had become agglomerated in a most 

 remarkable manner by hydrogenisation ; under ordinary 

 circumstances the metals shown existed in the form of 

 fine powders, but, as soon as charged with hydrogen, 

 become agglomerated. 



The fifth room, or Principal Library, is by far the largest 

 apartment of the suite. Mr. C. V. Walker's electrical 

 apparatus for carrying out the "block system," or "space 

 intervals," betsveen trains on the South-Eastern Railway, 

 was here displayed. Messrs. Tisley and Spiller exhibited 

 their compound pendulum apparatus in action, and distri- 

 buted cards with the exquisite curves described upon 

 them. This firm exhibited also the beautiful triple com- 

 bination double-image prism belonging to Mr. Spottis- 

 woode. Mr. E. B. Tylor's ingenious apparatus for illus- 

 trating refraction (already described in these columns) 

 was exhibited in this room.* We observed also some 

 splendid gold crystals exhibited by Mr. W. C. Roberts, 

 Chemist to the Mint; Mr. W. H. Barlow's " Logograph," 

 a recording instrument for showing the pneumatic action 

 accompanying the exercise of the human voice ; and a 

 pair of gyrostals exhibited by Prof Sir William Thomson. 

 Messrs. Negretti and Zambra exhibited their ingenious 

 thermometer for recording deep-sea and atmospheric 

 temperatures, already described in NATURE. Mr. John 

 Browning exhibited a good collection of apparatus. Mr. 

 G. P. Bidder's micrometer, a most ingenious device 

 for observing the transit of very faint stars, in which the 

 spider lines, capable of the usual micrometer movements, 

 are illuminated by a side light, and are reflected into the 

 eye-piece by a mirror, thus appearing bright upon a dark 

 ground, and by interposing coloured glasses between the 

 lamp and the spider lines can be coloured at pleasure. 

 Sir Charles Wheatstone's new photometer is well worthy 

 of notice : the screen slides along the divided scale and 

 its motion causes the increased overlapping of two sliding 

 wedges of neutral-tint glass. The hght is looked at 

 directly through a hole in the screen, and the latter 

 moved along the scale till the light just ceases to be 

 visible. We noticed also a micro-spectroscope of very 

 good definition, showing the absorption spectrum of 

 cantharides. Mr. Apps exhibited a model aad diagram 

 of a fireproof building, and a model of an improved 

 apparatus for indicating the speed of revolving shafts, 

 both being the inventions of Sir David Salomons. 



* We should recommend lecturers using this apparatus to see that the 

 wood is well seasoned ; the one exhibited soon ceased to act satisfactorily, 

 owing to the warping of the board. 



The plan for rendering buildings fireproof consists in 

 laying on water-pipes between the walls and floors of the 

 building, these pipes being self-acting by means of fusible- 

 metal plugs or electrical communications. The last- 

 nained model is an application of the ordinary governor 

 balls, which are connected with the shaft, and by a system 

 of levers, with an index, which moves up a graduated 

 scale. A double-action spectroscope with a divided 

 object-glass, made by Grubb, of Dublin, was shown and 

 explained by Lord Lindsay ; this instrument is intended 

 by its owner to be attached to a large equatorial for the 

 observation of stellar spectra. Among other noticeable 

 things in this room we may mention the Megohm, one 

 million British Association units, by Messrs. Elliott 

 Brothers ; Mr. George Barnard's highly artistic water- 

 colour drawings and the copies of sacred Icons of the 

 Greek Church in Russia, and photographs by Mr. John 

 Leighton. Col. Stuart Wortley's photographs from life 

 are high examples of art, and the group of living corals 

 {Astroidcs calicula) from the Bay of Naples, exhibited by 

 the Crystal Palace Aquarium Company, attracted large 

 numbers of admirers by their beauty. At 10 o'clock Dr. 

 R. Norris, of Birmingham, exhibited in the meeting-room 

 experiments to illustrate a form of contractive energy 

 which displays itself in various substances. Among other 

 things the Doctor showed that the statement that india- 

 rubber contracts by heat is incorrect ; this substance, it 

 is true, contracts in the direction of its length, but it ex- 

 pands in breadth at the same time, thus resembling the 

 so-called contraction of muscular fibre. 



In soirees of this kind experiments illustrative of new 

 chemical discoveries are generally " conspicuous by their 

 absence." This surely cannot be due to the fact that the 

 science does not permit of public demonstration; it arises 

 rather from the " messy " nature of the materials employed 

 by chemists, thus precluding the introduction of chemicals 

 into such rooms as are devoted by the Society to their 

 gatherings. We are of opinion that in not fitting up and 

 adding to their now noble apartments a laboratory, an 

 omission has been made which may be regretted in the 

 future. 



THE LECTURES AT THE ZOOLOGICAL 



SOCIETY'S GARDENS 



II. 



IN the second and third of his lectures On the Geogra- 

 phical Distribution of the IMammalia, delivered on 

 the Tuesday and Friday of last week, Mr. Sclater de- 

 scribed in detail the ranges of the difterent orders of 

 terrestrial mammals ; and to avoid unnecessary repetition, 

 employed the well-known system of division of the earth's 

 surface, proposed before the Linnean Society in 1S57, from 

 a study of the bird class, according to which there are 

 six regions — (i) 'Y\ift Pahra)xtic, including Europe, Africa 

 north of the Atlas Mountains, and Northern Asia. (2) 

 The Ethiopian, including all Africa south of the Atlas 

 Mountains, and the southern part of Arabia. (3) The 

 Indian, including Asia south of the Himalayas, Southern 

 China, and the Indian Archipelago. (4) The Australian, 

 including Australasia. (5) The Acarctic, including North 

 America down to the centre of Mexico ; and (6) The 

 Neotropical, including South and Central America. The 

 following is a summary of his remarks. 



Among the monkeys the anthropoid apes inhabit equa- 

 torial Africa, where the gorilla and chimpanzee are found ; 

 Sumatra and Borneo are the ho.ne of the orang outang ; 

 while the eastern portion of India, Burmah, and the Indian 

 Archipelago constitute the habitat of the various species 

 of gibbon. The catarrhine monkeys, including the green 

 monkeys [Ccrcopit/ici), and the macaques inhabit Africa 

 and India respectively ; the latter, however, extending 

 into Africa north of the Sahara, as far as Apes Hill and 

 the Rock of Gibraltar. The platyrrhine monkeys, among 



