Feb 2 1, 1884] 



NA TURE 



391 



this branch of science his peculiar study, was appointed by the 

 Board of Longitude to make astronomical observations m this 

 country." The observatory was erected as soon as the colonists 

 landed, but, being found small and inconvenient, a new one for 

 the better reception of the insti-uments and tlie residence of 

 Lieut. Dawes was built of stone, for which ample materials were 

 found upon the spot. 



The comet to which reference is here made was that of 

 1661, supposed to have been identical with the comet of 1532, 

 and again expected about the end of 1788 or beginning of 1789. 

 It is not difficult to explain how this body came to be associated 

 with the arrival of the first Australian colonists. Halley, who 

 had calculated the orbits of the comet observed by Apian in 

 1532, and that observed by Hevelius in l66i, gave very similar 

 elements in his " Synopsis of Cometary Astronomy." Pingre 

 considered the comets identical, and thought he had recognised 

 several previous appearances, as detailed in his "Cometographie," 

 which was published in 1783. Maskelyne appears to have 

 adopted Pingre's opinion, and was at the trouble of preparing 

 sweeping epliemerides, which he communicated to the Royal 

 Society, and -we may conclude that it was through his interest 

 with the Board of Longitude that Lieut. Dawes was supplied 

 with instruments and charged with a search for the comet. Mr. 

 Russell says there is no record of what was done at the Dawes' 

 Point Observatory, but since the comet was not observed as 

 expected, we may infer there were only negative results to be 

 reported, though Lieut. Dawes did occupy himself in other ways 

 to assist in the progress of the colony. 



CHEMICAL NOTES 



The water supply of Boston (U.S.A.) became contaminated 

 about a year ago with some substance or substances which im- 

 parted to it a peculiarly nauseous odour and taste. Chemical 

 examination resulted in showing a large percentage of "albu- 

 minoid ammonia," and also that the "free ammonia" increased 

 somewhat rapidly when the water was kept. The production of 

 ammonia, and aUo the odour and taste, was finally traced to the 

 decomposition of a freshwater sponge (Spongilla Jluviatilis, 

 Anct.) present in large quantities on the sides and bottom of one 

 of the storage basins ; removal of this sponge w as followed by 

 improvement in the water (see Analyst, viii. p. 184). 



Prof. Cleve describes, in the August number of the jour- 

 nal of the C/ic-mical Society, methods for extracting and purifying 

 the earth sama/'ia. From determinations of the amount of 

 sulphate obtained from quantities of this oxide, Cleve deduces 

 the number 150 as the atomic weight of the metal samarium. 

 Various salts of samarium are described ; the metal is closely 

 allied to didymium. 



Hartley showed some time ago (C.S.J. Trans, for 1882, 

 p. 84 et seq.) that the ultra-violet spectra of elements belonging 

 to the same series (in the nomenclature of the periodic law) ex- 

 hibit fairly marked analogies as regards general character ; recent 

 observations of the spectrum of beryllium and comparison of 

 this spectrum with that of allied metals have led Hartley to 

 the conclusion that this metal probably belongs to the group 

 which contains magnesium, calcium, &c. , and not to that con- 

 taining aluminium, scandium, &c. But if this is so, oxide of 

 beryllium must be represented as BeO, and the atomic weight of 

 the metal — about which there has lately been so much dispute — 

 must be taken as 9 {C.S.J. Trans, for 1883, p. 316). 



V. Meyer has recently separated, from benzene oils, a com- 

 pound to which he gives the name of Thiophen. The composi- 

 tion of this body is represented by the formula C4H4S ; it presents 

 the closest analogy in general reactions with benzene, yielding a 

 sulphonic acid, a metliyl derivative, &c. ; it reacts with diketones 

 to form highly coloured componnds. The further study of this 

 interesting compound, now being carried on in Prof. Meyer's 

 laboratory, is likely to lead to important results {Bcriihte, xvi. 

 2968). 



OSTWALD has recently made a further advance in his study of 

 chemical affinity. He has examined the action of acids on 

 methylic acetate, determining the velocity-coefficients of various 

 acids, and from these calculating the relative affinities of the 

 acids in terms of hydrochloric acid taken as too. His results 

 are entirely iu keeping witli the theory of Guldberg and Waage, 

 and confirm the supposition that each acid possesses a specific 

 affinity constant. The determination of affinity constants for 



groups of compounds must evidently be a work of preeminent 

 importance to chemical science. Ostwald's results, e.g. for acetic 

 and trichloracetic acids, enable us to see that in these constants 

 we shall find materials for constructing a theory which will repre- 

 sent the connection between molecular structure and reactions as 

 resting on a real basis, and not, as is done at present, on a purely 

 formal conception {J . fiir pract. Chem. (2) xxviii. 449). 



A NUMBER of redeterminations of atomic weights have recently 

 been published. The most important are these : — 

 Thorpe, Ti - 48-0, Berichte, xvi. 3014. 

 Baubigny, Ni = 5875, Compt. Rend, xcvii. 951. 

 ,, Cu = 63-46, ,, ,, 906. 



Brauner, Te = I2S'0, abstract in Berichte, xvi. 3055 (original 



in Russian). 

 Marignac, Bi = 2o8'l6, Archiv. des Sci. Pkys. et Nat. (3) x. 5. 

 Mn= 55-07, 

 Zn = 65-29, 

 Jig = 24-37, 

 Lowe, Bi = 207-33, Zeitschr. Anal. Chem. xxu. 489. 



It is known that Dr. Landolt, after laborious researches into 

 the refracting power of chemical compounds, arrived at the con- 

 clusion that it may be expressed, for organic bodies, by a very 

 simple equation : the refracting power of the compound is equal 

 to the sum of the same powers of carbon, hydrogen, and oxygen, 

 multiplied each by the number of atoms of each of these bodies 

 which enter into the compound. This law proved, however, 

 not to be quite exact with regard to several organic bodies, and 

 the researches of Herr Bruhl established that in the lower com- 

 pounds the refracting power received from the equation must be 

 increased by two units for each double pair of atoms of carbon. 

 These results had been arrived at with liquid compounds. As to 

 the solid ones, which were the subject of the researches of Dr. 

 Gladstone, it was desirable to pursue these researches to the 

 same degi-ee of accuracy as the researches of Landolt and Bruhl. 

 M. Kanonnikoff has prosecnted this work on a great many 

 solid bodies belonging to both groups of the fatty series, the aro- 

 matic series and the group of terebenes and camphors. He 

 publishes now in the Memoirs of the Kazan University and 

 (abridged) in the Journal of the Russian Chemical Society (vol. 

 XV. fasc. 7) the results of his researches. It appears from them 

 that the method of determining the refracting power of a solid 

 from its solution, applied by Dr. Gladstone, is quite satisfactory, 

 the dissolved body not changing its refrangibility when dissolved, 

 and that the laws discovered by Landolt and Bruhl for liquid 

 bodies arc quite true also with regard to solids. This inquiry 

 at the same time enables M. Kanonnikoff to arrive at most 

 interesting conclusions as to the structure of the investigated 

 bodies. 



The atomic weight of tellurium not corresponding to what it 

 ought to be according to Prof. MendeleefPs theory of periodicity, 

 M. Brauner has tried to determine it again with greater accuracy. 

 The chief difficulty is to have the tellurium free from selenium, but 

 this .difficulty has been overcome, and the body has been obtained 

 in beautiful crystals. As to Berzelius's method for the transfor- 

 mation of tellurium into anhydride, M. Brauner discovered that 

 it is liable to considerable losses, and to avoid them he has had 

 to take the most minute precautions. The process w as controlled 

 also by transforming tellurium into a new salt, Te.iOjSOj, and 

 by the synthesis of the teUuric copper, Cu.jTe. The results are 

 four series of figures varying from 124-94 to 125-40, which would 

 give, on the average, an atomic weight of 125, that is, 

 corresponding to the theory. 



We find, in the last number of the Journal of the Russian 

 Chemical Society, an interesting theory of solutions, by M. 

 Alexeyeff ; the forces of gravitation, cohesion, and chemical 

 affinity being considered as three different degrees of one single 

 force, v.diich differ from one another only by the distances at 

 which the action of the force is exercised. M. Alexeyeff asks, 

 Which of ihtse two last forces, of cohesion or of chemical 

 affinity, is manifested in solutions? and pronounces himself for 

 the former. The simplest cases of solutions are, in fact, those 

 where there is no chemical aftinity between the bodies dissolving 

 and dissolved. Such cases were well known long since for gases 

 and solid bodies. The solution of gases in solid bodies is quite 

 analogous to imbibition of solids with liquids, and the much 

 greater solubility of gases in liquids may be easily explained by 

 the easier penetration of gases between the molecules of a liquid ; 

 the law of solubility of gases given by Dalton is perfectly 

 agreeable with the supposition that the dissolved gases maintain 



