I40 



NATURE 



[June 17, 1875 



ammosia to sulphate of magnesia, &c. ?" — The President gave 

 several experimental illustiations of the time required for double 

 decomposition. He showed that ferric chloride and sulphocyanide 

 of potassium react instantly, that citrate of iron and meconic 

 acid, chloride of platinum and iodide of potassium, react gra- 

 dually. The rate of change really depends on the degree of 

 rapidity of the inter-difiusion of the salts. It is also affected to 

 a very great extent by temperature. The following numbers 

 illustrate the rate at which sulphate of strontium is deposited on 

 the addition of sulphate of calcium to a solution of nitrate of 

 strontium. : — 



Cloud in 4 minutes 



0'07i grms. ,, 20 ,, 



0-130 „ ,, 60 ,, 



0303 ,, ,, no ,, 



0-497 „ „ 170 „ 



o'659 „ ,, 1270 ,, 



The total amount of salt which could be formed being i"5 grms. 



Astronomical Society, June 11. — Prof. Adams, president, 

 in the chair. — Mr. Lecky explained the use of two ancient 

 instruments he had given to the Society. The smaller one was 

 known as a night dial ; it was used about the end of the sixteenth 

 century for finding the time at night by the position of the 

 pointers of the Great Bear. The observer stood with his face to 

 the north, and the instrument was held in one hand, so that a 

 line upon it was by estimation vertical to the horizon ; and with 

 the other a moveable arm like a clock hand was turned until it 

 was parallel to the direction of the pointers. The time was then 

 read upon the circumference of a boxwood circle, which had to 

 be set afresh for every night of the year. The other instrument 

 was a Backstaff, which was used at sea until the invention of the 

 sextant for determining the sun's altitude. The observer in using 

 it stood with his back to the sun (whence its name), and he 

 measured the arc between the sun's place and the opposite horizon 

 through the zenith. The instrument which was in use before this 

 was a very simple contrivance, being merely a pole along which 

 a moveable bar at right-angles was shifted, until the cross-bar 

 subtended the same angle when looked at by the observer with 

 his eye at the end of the pole as the sun's altitude. Such 

 contri'/ances were called Forestaffs, and were in use at sea until 

 1591, when Capt. Davis invented the Backstaff. — Mr. Marth 

 exhibited a drawing of the orbits of the satellites of Saturn as 

 they will be seen from the earth about the middle of August 

 next, Avheu there will be a conjunction of the satellite lapitus 

 with the ring and ball of Saturn. Mr. Maith was anxious that 

 observations of this conjunction should be made by the possessors 

 of large telescopes, in order to afford data for the improvement 

 of the theory of the satellites of Saturn. — A paper was read by 

 Mr. Knobel on an instrument for determining the magnitudes of 

 stars. — Mr. Christie said that the probable error in determin- 

 ing the magnitude of a star with his photometer amounted to 

 only the twentieth of a magnitude, but that the probable error 

 varied for stars of different colours, owing to the effect of con- 

 trast with the light of the sky, which caused a red star to be 

 more easily distinguished when its light was diminished than a 

 star with a blue tinge. 



Anthropological Institute, June 8. — Col. A. Lane-Fox, 

 president, in the chair. — Capt. Richard F. Burton, H.M. 

 Consul at Trieste, read two papers on Ancient Remains in 

 Dalmatia, viz., " The Long Wall of Salona" and "The ruined 

 cities of Pharia and Gelsa di Lesina." Salona was the Roman 

 metropolis of Dalmatia, of which southernmost province of 

 Austria, Spalato was at present the natural, and Zara the arti- 

 ficial and political capital. The ' ' long wall " was of doubtful 

 and debated origin, and a reference to numerous ancient and a 

 few modem writers on it was made to show the obscurity in 

 which it still remains. The author gave an account of his 

 explorations, with detailed measurements of the ancient struc- 

 ture, called by some " Cyclopean," and especially pointed out 

 the great variety of stone dressing it presented, which would 

 afford valuable evidence in determining the style and perhaps the 

 date of the work. His conviction that the long wall of Salona 

 was Greek and pre- Roman rested very much upon the fact that 

 similar constructions exist in the neighbourhood. In the island 

 of Lesina the two ruins visited and described by Capt. 

 Burton presented a remarkable resemblance, amounting almost 

 to identity, to the long wall of Salona, and suggested that 

 -they were all the work of a single people, and that people 

 not the barbarous Illyrians, but the comparatively civihsed 

 Creeks. Only two flint implements had been found, and those 



were discovered at Salona, near Spalato. The exploration of 

 the Dalmatian Islands was attended with much difficulty ; the 

 scarcity of water was an evil to be met, and a Slavic guide 

 was necessary unless the traveller could himself speak Slavic, for 

 the inhabitants all belong to that race. The islands never 

 having been previously explored (as far as the author was aware) 

 by Englishmen, there was a large field of research for the anti- 

 quarian as well as the more general anthropologist 

 Paris 

 Academy , of Sciences, June 7. — M. Frdmy in the chair. — 

 The following papers were read : — On the different effects pro- 

 duced by the same temperature upon the same species of plants, 

 in the north and in the south, by M. A. de Candolle. — 

 Researches on magnetic rotatory polarisation, by M. Henri 

 Becquerel. — On a new method and a new instrument for tele- 

 metry (quick measurement of distances), by M. Giraud Teulon. 

 — On the transformation of the camphor of Laurima into cam- 

 phene, and reciprocally of the camphenes into camphor, by M. 

 J. Riban.— -A note, by M. J. Ponomareff, on thiammeline, a 

 new derivative of persulphocyanogen. — On the dissociation of sul- 

 phocarbonate of potassium in the presence of ammonia salts, by 

 M. Rommier. — On the theory of revolution surfaces which, by 

 way of deformation, can be superposed on one another, and each 

 on itself in all its parts, by M. F. Reech.— Communications on 

 Phylloxera, by several gentlemen. — Several papers of minor 

 interest, competing for the prize of Medicine and Surgery. 

 —On the geographical position of the island of St. Paul, by 

 M. Mouchez ; he finds the latitude to be 38° 42' 50" 796 S. 

 (with a probable error of o" 03), and the longitude, 5h. om. 49s. 

 (probable error, 4s.).— On fluorcne and the alcohol derived from 

 the same, by M. Ph. Barbier. — Researches on taurine, by M. R. 

 Engel. — On the bibromide of angelic acid, by M. E. Demarcay. 

 — On three observations of accidents fromj lightning, by M. 

 Passot. — Analysis of the mineral coal of the Suderoe Island 

 (one of the Faroes), by MM. Bechin and Ch. Mene. — Remarks 

 by M. Tresca, on a projected atmospheric post between Paris 

 and Versailles. — A note by M. Emm. Liais, on the parallax 

 of the sun. — M. Vibraye then drew the Academy's attention to 

 the apparition of a destructive hemipterous insect in the vine- 

 yards of the Loir et Cher Department. The insect is very 

 similar to Phytocoris gothicus. — Remarks by M. J. de Cossigny, 

 on waterspouts. — On a new propeller of steamships, by M. E. 

 Lehman. 



BOOKS AND PAMPHLETS RECEIVED 



BRiTisH.-;-Encyclopffidia Britannica, 9th edit., vol. ii. (A. and C. Black). 

 — On the Principles and Management of the Marine Aquarium : Wm. R. 

 Hughes, F.L.S. (John Van Voorst).— The Life and Growth of Language. 

 International Series : W. Dwight Whitney (Henry S. King and Co.)— First 

 Annual Report of the Yorkshire College of Science, Leeds.— The Positive 

 Philosophy of Auguste Comte : freely translated and condensed by Harriet 

 Martineau. 2 vols. (Trukner) —The Geological Evidences of the Antiquity 

 of Man reconsidered— an Essay by Thos. Karr Callard, F.G.S. (Elliot 

 Stock).— Corals and Coral Islands : Jas. D. Dana (Sampson Low and Co.)-^ 

 An Introduction to the use of the Mouth-Blowpipe : Scheerer and Blandford 

 (Frederic Norgate). 



CONTENTS PxoB 



Croll's "Climate AND Time" i^i 



Hu.DEBRANDssoN ON Ui'PBR Atmospheric Currents 123 



Our Book Shelf: — 



" The Zoological Record " 12^ 



Letters to the Editor :— 



SystemsofConsanguinity.— Sir John Lubbock, Bart., F.R.S. . 134 

 Attraction and Repulsion caused by Radiation —William 



Crooke-s, F.R.S. .. . J25 



American Indian Weapons.— Col. A. Lane-Fox ' 125 



Hardened Glass.— Henry Pocklington 125 



The House-fly— A Query.— Harrovian 136 



Our Astronomical Column :— ■ 



Variable Stars ^g 



The Binary Star n Coronse Borealis '. .* 126 



Proper Motion of B. A. C. 793 127 



Minor Pl.anet No. 146 '. ! .' 127 



Science in Germany ".!!.! i .'! 127 



Zoological Nonsense !...*'.! ii8 



Lectures at the Zoological Gardens, VII. : June 10.— Prof. Mivart 



on Kangaroos j2g 



Magneto-Electric Machines, II. By Dr. Andrews, F.'r.'s. 'nVit'h 



Illustraiions) j,q 



On the Temperature of the Human Body during Mountain- 

 climbing ,^2 



Notes '. I *..*..'.!'. 133 



Recent Progress in our Knowlkdge of the Ciliatk Infusoria. 



By Dr. G J. Allman, F.R.S 136 



Scientific Serials 138 



Societies and Academies .. i ,,..,. \ ,'.'.. ', 139 



Books and Pamphlets RkcbiVkd . . . ; 140 



