y une 



>i] 



NATURE 



vation of the neighbours of W.B. 7h. 1029. It may be ulti- 

 mately found that Schmidt's star affords an extreme illustration 

 of the laws affecting variables of the class of U Geminorum. 



Can Mr. Baxendell put anything upon record as to dates when 

 he has examined the vicinity, which may bear upon the length 

 of invisibility of Schmidt's star ? 



The Comets of iSio and 1863 (v).- At the suggestion of 

 Prof. Bruhns new elements of the Comet of 1810 have been 

 investigated by Herr Thraen from the ten observations made at 

 Marseilles by Pons, who discovered the comet on August 22. 

 We had previouly orbits by Bessel acd Triesnecker. The 

 observations are unfortunately afiected with considerable errors, 

 but the following appears to be the best system of elements 

 obtainable from them ; — 

 Perihelion passage, iSio, October 6-23793, M.T. at Greenwich. 



Longitude of perihelion 63 46 43 ) M. Eq. 



„ Ascending node ... 308 50 31 ( l8lo-o 



Inclination 62 55 39 



Log. perihelion distance 9'9866o3 



Motion— direct. 

 We subjoin Prof. Weiss's parabolic elements of the Comet 



1863 (v), discovered by Respighi at Bologna on December 28; 

 notwithstanding their striking resemblance to those of the comet 

 of 1 8 10, Prof. Weiss was inclined to consider the comets dif- 

 ferent : he tried an ellipse with period of fifty-three years, but 

 the comparison of the observations in January, 1S64, was not so 

 satisfactory as with the parabola. Michez, by direct calculation 

 upon a month's observations, obtained a period of 109 years. 



Perihelion passage, 1863, Dec. 27'76369, M.T. at Greenwich. 



Longitude of perihelion 60 24 28 ) M. Eq. 



,, Ascending node ... 304 43 26 ( i864'o 



Inclination .. 64 28 46 



Log. perihelion distance 9'887344 



Motion — direct. 

 There is perhaps room for a further and more minute discussion 

 of the observations of 1863-64, though the result may be adverse 

 to the idea at one time entertained that the comets are identical. 

 There w as a near approach to the Earth at the end of January, 



1864 (o'lS), and the perturbations from this cause will require to 

 be taken into account in a more refired determination of the 

 crbit. The comet was observed at Krem-miinster till February 

 14; Prof. Julius Schmidt sought for it ineffectually at Athens on 

 March 4, 



Probably we have, in the case of these comets, an illustration 

 that mere similarity of orbits, even though it may be pretty close, 

 is not to be regarded as proof of identity. 



CHEMICAL NOTES 

 Herr Drechsel claims [Journal Pracl. Chem.) to have 

 converted ammonium carbonate into urea by the continued action 

 of a galvanic current, the direction of which is rapidly reversed 

 by a self-acting commutator. 



A MODIFICATION in the process ior manufacturing iodin^ 

 from Fcaweed is described by MM. Pellieux and Allary (Bull- 

 Soc. C/ihn.), whereby, it is said, nine times more iodine is 

 obtained than by the older process. The unbumt seaweeds are 

 allowed to ferment in large heaps ; the liquor which drains off 

 is concentrated and dialysed in Dubrunfaut's apparatus before 

 evaporation. The plants are burnt without further drying. 



Several of the timed preparations of the St. Louis Canning 

 Company have been examined by Mr. Wigner (Analyst). The 

 dietetic value of the corned beef is about t\vice that of boneless 

 fresh beef ; the cooked ox-tongues contain less salt and more 

 nutritive matter tban ordinary dried tongues. Succotash, an 

 American preparation of haricot beans, Lima beans, and maize, 

 cooked in the tin, with addition of a little fat, is recommended 

 as a good sjecimen of boiled vegetable food. 



The number I97'2 is generally accepted as the atomic weight 

 of platinum; Ilerr Seubert has very recently shown, in the 

 Bcricht€ of the German Chemical Society, that this number is 

 vei-y probably too high. As the mean of thirty-nine closely- 

 agreeing results, Herr Seubert obtains the number I94'46. If 

 this number is accepted the atomic weight of platinum is less 

 than that of gold. 



Herr Th. Wilm has studied {Berliner Berichtc) the action 

 of finely-divided palladium, platinum, and rhodium, when heated 

 in a stream of coal-gas. He finds that these metals decompose 

 the gas, that when palladium is used a deposit of carbon takes 

 place at some distance from the heated metals ; that with pla- 

 tinum the carbon is deposited on the metal, but that on heating 

 in a stream of air the carbon is burnt completely away, and the 

 metal remains in its original form ; with rhodium, however, the 

 carbon appears to form a compound, the volume of which is 

 considerably greater than that of the metal itself ; this compound 

 is decomposed only w ith difficulty, leaving metallic rhodium in 

 a much more bulky form than that which it possessed before the 

 experiment. 



MicHAELis AND ScHULTE describe, in Berliner Bcrichte, a 

 new derivative of benzene, analogous with azobenzene, but 

 containing arsenic in place, of nitrogen. Arsenobenune, 

 CjHj— As=As— CjHs, produced by the action of reducing 

 agents on CjHsAsO, forms slightly yellow coloured needles 

 which are insoluble in alcohol and ether, and crystallise well 

 from hot xylene. The new compound, unlike azobenzene, 

 readily takes up two atoms of chlorine, forming — 

 CeH,— As— As-CgHj. 



CI CI 



Dr. A. R. Leeds describes, in the same journal, the action 

 of nascent oxygen, ozone, and hydrogen peroxide on benzene. 

 Nascent oxygen was produced by the action of moist phosphoras 

 on air in presence of benzene ; if the action proceeds in sunlight 

 a large quantity of phenol is produced, together with oxalic acid ; 

 but if in diffused daylight no phenol is formed. Phenol was 

 also produced by the direct action of hydrogen peroxide on ben- 

 zene, but when ozone acted on the same hydrocarbon, carbon 

 dioxide, acetic, formic, and oxalic acids were produced, but r.o 

 phenol was formed. 



In a preliminary note in the Berliner Berichie, Herr Donath 

 states that the ordinary method of volumetric determination of 

 oxidisable substances by titration with potassium permanganate 

 in presence of acid may, in many cases, be advantageously re- 

 placed by an inverse process in which a neutral solution of the 

 substance to be oxidised is added to a strongly alkaline solution 

 of permanganate, whereby oxidation occurs with precipitation 

 of manganese dioxide : — thus with manganese salts and with 

 chromic salts the following actions occur : — 



(1) 3MnO -1- MnjO; = sMnO.,. 



(2) Cr^Oa -F MuaO, = 2Cr03 -(- 2Mn02. 



A METHOD for determining molybdenum in molybdates is 

 described by Danesi (in Atti della AccaJemia), based upon the 

 fact that hydriodic acid is decomposed by molybdenum tri- 

 oxide with separation of iodine. A weighed quantity of the 

 molybdate under analysis is mixed with hydrochloric acid and a 

 solution of potassium iodide ; the amount of iodine liberated 

 in the reaction is determined by titration with sodium thiosul- 

 phate solution. The results are very accurate. 



In the same journal a method for determining nitrites and 

 nitrates in the same solution is described by Piccini : the method 

 is based on the decomposition of ferrous chloride by nitrous and 

 nitric acids with evolution of nitric oxide, and on the greater 

 readiness with which this decomposition is accomplished by 

 nitrous than by nitric acid. 



Herr M. Groger has prepared {Wien. Akad. Bcr.) several 

 sulphochromites, i.e. salts of a chromcus acid in which oxygen is 

 replaced by sulphur ; the following salts are mentioned among 

 others : — 



Na2Crs,S4 I CdCraSj 



AgoCrjS^ I SnCr.,S4. 



The re are about 300 known optically active carbon compounds. 

 The specific rotatory power of but seven of these has been accu- 

 rately determined for the pure substance, and for solutions of the 

 substance in various solvents in all possible degrees of dilution ; 

 these seven are tartaric acid and ethyl tartrate, cane-sugar, 

 dextrose, terpene from turpentine oil, nicotine, and camphor. 

 The nature and qu.antityof the solvent employed exerts a marked 

 influence en the rotatory power of the active compound ; as a 

 contribution to this subject the measurements made by Herr A 

 Becker (Deut. Chem. Ges. Bcric/ae) of the rotatory power of 

 asparagine and aspartic acid deserve mention. An aqueous 

 solution of either compound exhibits left-handed rotatoiT powers ; 



