362 



NATURE 



[Fed. 22, 1877 



Kiel on the loth, and one made at the Imperial 'Observatory at 



Strasburg on the i5tb, and communicated by Prof. Winnecke : — 



Ptrihelion Passage, January 19-18017, Greenwich M.T. 



Longitude of the perihelion ...200 5 2) Apparent 



,, ,, ascending node 187 14 22 ) Equinox, Feb. 10. 



Inclination to the ecliptic ... 27 5 13 

 Logarithm of perihelion distance 9 '907086 



Heliocentric motion — retrograde. 



According to this orbit the comet was distant from the earth, at 

 the time of discovery, 0-45, the earth's mean distance from the 

 sun being taken as unity. Its apparent path in the heavens 

 about the perigee, and up to March 6, will be sufficiently de- 

 fined by the following ephemeris : — 



For Greenwich Midnight. 



Right North Polar Distance rrom 



Ascension. Distance. the Earth, 



o / o / 



February 13 262 50 70 22 0-324 



15 266 21 57 2 0-292 



17 272 10 41 42 0279 



19 283 10 26 48 0-288 



21 307 40 15 35 0-318 



. 23 359 21 II 52 0363 



25 27 41 15 9 0-418 



27 42 51 19 43 0-479 



March 6 58 51 31 i 0-719 



From the above figures it will be seen that the diurnal motion, 

 about the middle of the present month, amounted to 8° in arc of 

 great circle ; the comet was nearest to the earth soon after mid- 

 night on the 17th. At the time of perihelion passage it would 

 be situated about 6° to the east of Ant ares, distant from the 

 earth 1-15. 



There is a certain similarity, but by no means a striking one, 

 between the elements of this comet and those of the comet of 

 1590, observed by Tycho Brahe, the orbit of which was first 

 calculated by Halley, and, in 1846, after a new reduction of 

 Tycho's observations, by Mr. Hind {Ast. A^ach., No. 584). It 

 may be worthy of remark that shortly after the passage of the 

 ascending node, the comet of 1590 approaches very near to the 

 orbit of the planet Venus, the least distance not exceeding 0-04. 

 Still the differences between the elements of the comets of 1590 

 and 1877, especially in the perihelion distance, are material. 



The "Berliner Astronomisches Jahrbuch." — Under 

 the active superintendence of Prof. Tietjen, the Berliner Jahr- 

 btuh continues the heavy labour involved in the preparation of 

 ephemerides of the extensive group of small planets, a work 

 which for many years past has been made its specialty. In the 

 volume for 1879 now before us, we have the places for 1877 of 

 151 out of the 172 actually known members of the group. No. 

 164, Eva, being the latest discovery included in the list. Also 

 the elements of their orbits and the opposition magnitudes, a very 

 useful addition towards the identification of these minute bodies 

 amongst the fainter stars. The portion of the volume devoted 

 to the small planets extends to 106 pages. The judicious transfer 

 of the ephemeris of the moon, derived from Hansen's Tables 

 from our Nautical Almanac, which appears between one and 

 two years earlier, to the pages of the Berliner Jahrbuch, after 

 adaptation to the meridian of Berlin, whereby a most serious 

 expenditure of time and labour is saved, has already been noted 

 in this column ; it is a step which no doubt assists materially in 

 completing the peculiar work of the Jahrbuch. 



The following are names which have been recently proposed, 

 for discoveries made within the last few years i No. 139 Juewa, 

 149 Medusa, 150 Nuwa, 155 Scylla, 160 Una, 16 1 Athor, 163 

 Erigone, 164 Eva. No. 162 is not yet named. 



Only four of these planets (in addition to two of the old mem- 

 bers) attain 8-5m. or upwards at their oppositions in 1877. 

 Ariadne, in opposition on July 24, approaches the earth within 

 about 0-84 of the earth's mean distance from the sun, and Iris, 



which at her opposition on November 18, is calculated to be 

 6"8m. or on the limit of acute unaided vision, will be distant 

 from us 0-86 — affording an opportunity which maybe utilised for 

 attempting direct measures of her diameter, though if we are not 

 mistaken some pretty satisfactory ' measures were made at a 

 favourable opposition a few years since, with a powerful refractor 

 in this country. This planet when near the earth has a decidedly 

 red light; at two oppositions within the last fifteen years it 

 might be identified amongst the neighbouring stars by this cir- 

 cumstance alone. 



CHEMICAL NOTES 



Absorption of Light in the Blood. — In a number of 

 cases of unintentional poisoning caused by carbon monoxide in 

 Berlin during the past winter, oxygen has been used as an anti- 

 dote. Dr. Bseblich, of Berlin, lately showed the desirability of 

 the method by means of spectroscopic proof in a public lecture. 

 As is well known, the spectrum of blood shows two well-defined 

 bands between Fraunhofer's lines D and E. By the absorption 

 of CO the position of these bands is very slightly changed in the 

 direction of the red part of the spectrum. The difference is more 

 strikingly shown by the addition of sulphide of ammonium. In 

 the case of healthy blood the two bands of the spectrum disap- 

 pear and are replaced bj a single one situated midway between 

 the positions of the former pair. Blood poisoned with CO shows 

 no change in the bands by the same treatment. If oxygen is, 

 however, added to it before the reduction with sulphide ol 

 ammonium, the characteristic spectrum of healthy blood is at 

 once produced. 



Physical Properties of Gallium. — M. Lecoq de Bois 

 baudran has introduced a new method for the extraction of this 

 metal, and has investigated some of its physical properties. Its 

 crystalline form is octahedral ; the mean of six experiments gave 

 as its melting point 30-15. Its specific gravity is 5-956; when 

 fused it has a silver lustre, but on solidifying it sho'Ars a tinge of 

 blue, losing its brilliancy. It is hardly acted on by nitric acid 

 when diluted with an equal bulk of water. 



Potassium Tri-iodide. — Mr. G. S. Johnson has recently 

 published an investigation on this body, which is prepared when a 

 strong solution of potassium iodide is saturated with iodine, and 

 the resulting liquid allowed to evaporate slowly over oil of vitrioL 

 The crystals are sometimes long and isolated, sometimes appear- 

 ing as hexagonal plates exhibiting a stepped arrangement like 

 those of potassium iodide. They have a steel-blue lustre, are 

 very deliquescent, fusing at about 45° C, and have a specific 

 gravity of 3-498. When the temperature Is raised above 100°, 

 iodine is freely evolved from the crystals, a white mass of pota?, 

 sium iodide alone remaining. On analysis the crystals yielded 

 90*2 to 90-4 per cent, of iodine and 9-2 per cent, of potassium ; 

 the theoretical quantities required, supposing the body to be 

 KT3, are iodine 90-692 per cent, and potassium 9-307 per cent, 

 An excess of water decomposes potassium tri-iodide, with pre- 

 cipitation of the most of the iodine ; the crystals, however, may 

 be dissolved in small quantities of water or alcohol, and re- 

 crystallised over sulphuric acid. 



Solution of Gases in Iron, Steel, and Manganese.— 

 MM. Troost and Hautefeuille have published in the Ann. Ckinu, 

 Phys., [5] vii., a reprint of their researches on this subject, pre* 

 viously published in other journals. When cast iron is fused 

 contact with silica or silicates, carbonic oxide is produced by thi 

 action of the iron carbide on silica ; the iron thus becomes richer 

 in silicon, the carbon diminishing. Melted cast iron seems to 

 occlude considerable quantities of hydrogen, this occlusion beingT 

 increased by the presence of manganese and diminished by the 

 presence of silicon. Carbonic oxide is not taken up to so great 



