April 6, 1876] 



NATURE 



449 



traces of chlorine can be discovered by dissolving at first a larger 

 quantity of oxide of copper in a bead of microcosmic salt ; if, 

 then, any substance containing chlorine be brought in contact 

 with the bead on the point of the blue jet, the blue flame of the 

 blow-pipe is coloured azure blue ; the same colour is even exhi- 

 bited when chloride of sodium and oxide of copper are heated 

 in the bead ; the yellow flame of the sodium is scarcely visible, 

 and does not conceal the azure blue flame. 



In making the above experiment, I immediately suspected 

 that the blue light imparted to the coal corresponds with the 

 light of the microcosmic bead, the chlorine of the salt combines 

 with the copper, which bums with the azure blue flame. 



To convince myself that the blue colour is not due to any 

 other cause, I took a charcoal fire free of copper, and threw salt 

 into it ; the salt gave a slightly yellow flame of sodium, and not 

 the minutest trace of a blue flame could be discovered, though 

 large quantities of salt were used, but on throwing the slightest 

 quantity of oxide of copper on to the charcoal, the azure blue 

 colour occurred instantly. 



The following chlorides, HCl, KCl, NH^Cl, BaClj, CaClj 

 which I had at my disposal, exhibited more or less a blue colour 

 when cast into a coal fire. T. N. Mullir 



Middleton St. George 



OUR ASTRONOMICAL COLUMN 



Double Stars. — Baron Dembowski communicates to 

 the Astronomische Nachrichten, Nos. 2,076-2081, his 

 later measures of double-stars, amongst which is a con- 

 siderable number of well known binaries. The measures 

 are given in a slightly modified form from that adopted 

 in most of the Baron's previous important communi- 

 cations, v/hich commenced in vol. 62 of the above 

 periodical. 



For the sake of facilitating a comparison with the best- 

 determined orbits of revolving double-stars, we extract a 

 few of the most recent Gallarate epochs or means of the 

 year's measures : — 



Name of Star. 



Castor 

 C Cancri . . . 

 J Ursse Maj. 

 V Virginis... 

 4 Bootis ... 

 J? Coronse Bor. . . 

 I Scorpii . . . 

 \ Herculis 

 70 Ophiuchi 

 SCygni ... 

 53062 ... 



Yeai'. 



... i875'25 

 ... 1875-14 

 .. 1875-27 

 ... 1874-93 

 ... 1874-89 



• 1875-41 

 . 1874-96 



• 1875-52 

 ■ 1875-52 

 . 1875-02 

 . 1875-67 



The orbits with which the above comparisons have been 

 made are by the following calculators ; the periods of 

 revolution are addsd. 



Castor 



C Cancri 



I UrsK Majoris 



7 Virginis . . . 



i Bootis 



T] Coronte Bor. 



^ Scorpii 



C Herculis ... 



70 Ophiuchi 



S Cygni 



23062 



Thiele ... 

 O. Struve 

 Hind ... 

 Thiele ... 

 Hind ... 

 Wijkander 

 Thiele ... 

 Duner ... 

 Schur ... 

 Behrmann 

 Schur ... 



996 -85 years, 



62-4 



60-68 

 185 01 

 168-9 



41-58 

 49-05 

 34-22 



94-37 

 415-1 

 112-64 



Comparisons are omitted in the cases of several binaries 

 the orbits of which have been worked up to about present 

 time, principally by Dr. Doberck, of Markree Observatory. 

 Mr. W. Plummer's orbit of C Cancri gives the angle 15° 

 greater than the measures, the distance nearly agreeing 

 The orbit of ^ Ursas Majoris by Dr. Ball, of Dunsink 

 Observatory, Dublin, is not available as printed in the 

 " Monthly Notices " of the Royal Astronomical Society 

 the excentricity being omitted, and the same element has 

 escaped also in Dr. Doberck's orbit of <r Coronae Borealis. 



The Equator of Mars. — Sir W. Herschel's deter- 

 mination of the position of the plane of the equator of 

 this planet, from observations made in the autumn of 

 1783, was communicated to the Royal Society in Decem- 

 ber of the same year. He found for the inclination of the 

 axis to the orbit, 61° 18', and therefore for the obliquity on 

 the globe of Mars, 28° 42' ; the inclination of the axis to the 

 ecliptic, so" A~', the north pole being directed in 1783 to 

 longitude 347° 47'. From these figures we deduce for the 

 ascending node of the equator of Mars upon that of the 

 earth (n) 48° 9', and its inclination thereto (i) 41° 27'. 



Olbers, from the observations of Schroeter and Hard- 

 ing, on the south polar spot upon Mars in October and 

 November, 1798, found for the longitude of this pole 

 172° 54'-7, and the latitude 60' 33'"2, and hence we have 

 for the ascending node of the equator on the orbit, 

 84° 54', and for the obliquity on Mars, 27" 57' ; the ascend- 

 ing node of the equator of Mars upon the terrestrial 

 equator 50* 29', and the inclination 39° 14'. 



But the determination which has been generally relied 

 upon as the best yet available is that made by Dr. Oude- 

 manns, now director of the Observatory at Batavia, from 

 measures by Bessel with the Konigsberg heliometer, 

 1833-37. For about 1834-0 he found the longitude of 

 the north pole of Mars 349° i', and its latitude 61° 9'. 

 The node of the orbit of the planet in the eclipiic being 

 at this time in 48° 16', and the inclination 1° 51', we have 

 for the ascending node of the equator of Mars on his 

 orbit, 80^ 50', and for the obliquity of the Martial ecliptic, 

 27° 16', and therefore for the ascending node of the equator 

 of Mars upon the terrestrial equator, 47° 34', and its in- 

 clination, 39^ 56'. Assuming these figures to apply to 

 1834-0, we get for 1877 — 



N = 47" 55' I = 39° 46'- 



A Southern Comet (.?). — The Wanganui Herali 

 (N.Z.), of January 20, says : — "What appeared to be a 

 small comet was visible in the south, in the constellation o: 

 Argo Navis, for about two hours last night, the rising 

 moon rendering it invisible. It was very small, and 

 appeared to be rapidly moving towards the east." The 

 summary number of the Melbourne Arsons of January 26 

 has no reference to the visibility of a comet, and the 

 above notice at present requires confirmation. 



PROF. FLOWER'S HUNTERIAN LECTURES 

 ON THE RELA TION OF EXTINCT TO EXIST- 

 ING MAMMALIA ^ 



VI. 



'T'HE order Cetacea is one of peculiar interest, having 

 ■■■ many specialities of structure, and being sharply 

 defined from all other groups, with no outlying or doubt- 

 ful forms at present Imown. Being purely aquatic ani- 

 mals, and all of considerable size, their remains are more 

 readily preserved than those of some other orders. None, 

 however, have been met with in the well-explored deposits 

 of the cretaceous seas, or indeed in any European strata 

 (with the doubtful exception of the cervical vertebrae of 

 Palceocetus from Ely), earlier than the Miocene. Abun- 

 dant remains are, however, found in various Miocene and 

 Pliocene marine beds, notably at Antwerp, in many parts of 

 France, Germany, especially the Vienna basin, Italy, and 

 South Russia. They are also found, though in a less 

 perfect condition, in the crags of the east of England. 

 In the Eocene deposits of the eastern states of America, 

 the strange and gigantic Zeuglodons occupy the place of 

 the ordinary Cetacea, which occur in the Miocene and 

 later ages. 



Among the existing members of the order there are 

 two ver>' distinct types, the toothed whales or Odontocetes, 



» Abstract of a course of lectures delivered at the Royal College of Sur- 

 geons "On the Relation of Extinct to Existing Mammalia, with Spedai 

 Reference to the Derirative Hypothesis," in condusion of the course of X873. 

 <See Reports in Natumc for that year.) Continued from p. 410. 



