2IO 



NA TURE 



[December 31, 1891 



When the crystals are placed in an atmosphere of chlorine they 

 at once liquefy, and the liquid becomes hot. The products are 

 carbon tetrachloride and liquid chloride of iodine, ICi, which 

 latter gradually volatilizes away in the form of the chloride, ICI3. 



CI4 + 4CI0 = CCI4 + 4ICI. 

 When heated gently in dry oxygen, it becomes decomposed 

 into iodine and carbon, which latter burns away to carbon 

 dioxide upon slightly raising the temperature. Melted sulphur 

 reacts with carbon tetra-iodide with considerable violence ; 

 vapour of iodine is evolved, carbon deposited, and iodide of 

 sulphur formed. If, however, powdered sulphur is warmed 

 with carbon tetra-iodide to 50°, iodide of sulphur and carbon bi- 

 sulphide are produced. Phosphorus acts with great energy upon 

 it, forming compounds which are still undergoing investigation. 

 Sodium and potassium react with incandescence, an alkaline 

 iodide and free carbon being produced. Mercury and silver 

 likewise attack it at the ordinary temperature, and very rapidly 

 upon warming. Warm hydrochloric and hydriodic acids attack 

 the crystals rapidly, with formation of iodoform and liberation of 

 vapour of iodine. A particularly interesting reaction is that 

 with fluoride of silver. When a quantity of this salt is placed 

 in a solution of carbon tetra-iodide in carbon tetrachloride 

 warmed to 50°, a regular evolution of gaseous carbon tetra- 

 fiuoride occurs. 



CI4 -f 4AgF = CF4 -f 4AgI. 



This reaction affords the readiest means yet discovered of pre- 

 paring carbon tetrafluoride. 



The additions to the Zoological Society's Gardens during the 

 past week include a Vervet Monkey {Cercopithecus lalandii ? ) 

 from South Africa, presented by Mr. J. Parr ; a Bonnet Monkey 

 {Macacus sinictis i ) from India, presented by the Rev. W. P. 

 Beckett ; a Black-faced Kangaroo {Macroptts inelanops 9 ) from 

 Australia, presented by Mr. P. Clark ; two Red-crested Finches 

 {Coryphosphingus cristatus) from South America, presented by 

 Commander W. M. Latham, R.N., F.Z.S. 



OUR ASTRONOMICAL COLUMN. 



The Secular Variation of Latitudes.— The American 

 Jotirnal of Science for December contains a paper on secular 

 variations of latitudes, read by Prof. George C. Comstock at 

 the Washington meeting of the American Association for the 

 Advancement of Science. The determinations of the latitude 

 of Greenwich made from the time of Flamsteed {1693) to now — 

 that is, over a period of very nearly two centuries — ^indicate a 

 very appreciable progressive diminution. But as the observa- 

 tions M^ere made with five different instruments, and are affected, 

 to an uncertain extent, by various sources of error, no definite 

 conclusion can be drawn from them. In the cases of the lati- 

 tudes of Pulkowa, Konigsberg, Washington, and Madison, 

 however. Prof. Comstock thinks there is definite evidence of 

 a change of latitude, and from an examination of numerous 

 absolute observations, and a reduction of recorded star-places, 

 he arrives at the data contained in the following table : — 



Longitude 

 Station. (from 



Greenwich). 



Pulkowa 

 Konigsberg . 

 Washington 

 Madison 



30-3 E. 

 20-5 E. 

 77-0 W. 

 89-4 W. 



Annual 



Variation 



of Latitude. 



- o'oo6 



- OC03 



-f 0042 



+ 0-043 



Computed 



Annual 



Variation. 



- 0007 



- O'OOO 

 -f 0044 

 -f 0041 



A least square solution of the observed data was made to 

 determine the most probable direction and amount of motion 

 of the Pole. The result was o"'044 along the meridian 69° W. 

 of Greenwich. The values contained in the last column of the 

 above table were computed from these elements. For the sys- 

 tematic investigation of the motion of the Pole it is suggested 

 that two stations in about the same latitude, but having longi- 

 tudes about 70° W. and 110° E. respectively, should have their 



NO. I 157, VOL. 45] 



latitudes simultaneously determined by zenith telescope observa- 

 tions of the same pairs of stars. "An annual motion of the 

 Pole of o"-045 will alter the difference of latitude of these 

 stations by twice this amount per year, giving a change in 

 the difference of latitude amounting to i" in eleven years — a 

 quantity which cannot possibly escape careful observation with 

 the zenith telescope or prime vertical transit. If similar obser- 

 vations be made 20° east of Greenwich, they will furnish the 

 best obtainable data for determining the direction of motion of 

 the Pole." All sources of systematic error can be eliminated 

 by the adoption of such a method, and our knowledge of secular 

 variations of latitude, as important to the geologist as to the 

 astronomer, will be of a more definite character than at present. 

 The Rotation of Venus. — Herr Loschardt sends us a 

 paper on Schiaparelli's hypothesis as to the period of rotation of 

 Venus-, presented by him to the Vienna Academy of Sciences 

 on March 12, 1891. He criticizes the conclusions drawn by 

 Schiaparelli from observations made by others and himself, and 

 points out that the observations made by Denning in 1881 favour 

 the old rotation period of 23d. 21m. rather than one of 224 

 days. Herr Loschardt has made a number of drawings of the 

 markings on the planet shown by his 3-inch refractor at Nako- 

 falva, and the discussion of them gives support, on the whole, 

 to Cassini's value of the rotation period. The chief reasons 

 which led to this conclusion are the differences between Per- 

 rotin's observations and those made at Nakofalva at different 

 hours in the same day, the circular form of polar patches, and 

 the ellipsoidal distribution of the atmosphere, which is said to be 

 the result of swift rotation. 



Stars having Peculiar Spectra.— In a communication 

 to Astronoviische Nachrichteii, No. 3070, Prof. Pickering re- 

 cords that the three stars tabulated below show bright lines in 

 their photographic spectra, and belong to the s-ame class as the 

 stars discovered by Wolf and Rayet : — 



Designation. R.A. igoo. Decl. Galactic Galactic 



" latitude. longitude. 



h. m. o / o / o / 



D.M. -f 55-2721 ... 22 15-0 ... 55 37 ... -o 50 .. 70 29 

 — ... 22 237 ... 55 46 ... -I 20 ... 71 38 



D.M. -f 56-28x8 ... 22 329 ... 56 23 ... -I 25 ... 73 3 

 It will be seen that these stars, like the 35 others of the same 

 class, fall near the central line of the Milky Way. 



THE TOWER OF BABEL AND THE 

 CONFUSION OF TONGUES} 



■yiTHO among the readers of ancient history has not pictured 

 to himself great Babylon, with its long straight streets at 

 right angles, its quays along the banks of the Euphrates, its 

 royal palaces, its double walls, and last, not least, its towers in 

 stages, dedicated to the various gods? The picture of grandeur 

 is one of which we can form an estimate only, but it must have 

 been magnificent beyond what was customary in those days, for 

 had not the great Nebuchadnezzar built it ? He describes at 

 great length what he had done for the city, for its walls, for its 

 streets, its temples, its towers, and its palaces. 



But there was a time when Babylon was not the great city. 

 At first a village settlement, it gradually arose to be the capital 

 of a powerful State, a progress that probably occupied 4000 

 years, not including the pre-historical period. The story of the 

 beginnings of this great city, which are lost in antiquity, is told 

 in Genesis, and forms one of the most charming of the legends 

 of the Bible. The Biblical account is given in the genea- 

 logical table just before "the generations of Shem," and ^eems 

 to be an interpolation to explain the numerous languages of the 

 world. What the source of the legend may be is uncertain, but 

 as a whole it is unique, for though its source is possibly Baby- 

 lonian, nothing like it has yet come from that country or from 

 Assyria. The so-called Babylonian legend of the Tower of 

 Babel seems to have nothing to do with the Biblical one — 

 indeed, the evidence all points to its referring to something 

 entirely different. 



" As they journeyed (so the Bible narrative says) in the East, 

 they found a plain in the land of Shinar." This land of Shinar 

 is generally regarded as the Sumer of the Babylonian and 

 Assyrian inscriptions. The Sumerians and Akkadians were of 

 a different stock from the Semitic inhabitants of the country, and 



Abstract of a Lecture by Theo. G. Pinches, before the London In- 

 stitution, December 3, 1891. 



