134 



NATURE 



[June 9, 1892 



a full and accurate knowledge of the qualities of the various 

 brands of pig-iron now on the market would be a prime re- 

 quisite ; none the less would a correct knowledge of mixing 

 be essential, while the rolling, scaling, and annealing would 

 all have to be very carefully attended to if satisfactory results 

 were to be attained." 



An important series of bibliographies relating to the more 

 prominent groups of the languages of the North American 

 Indians, by J. C. Pilling, is being issued by the Smithsonian 

 Institution. The numbers concerning the Eskimauan, Siouan, 

 Iroquoian, and Muskogean families are already known to 

 students of these languages ; and now a fifih number, giving the 

 bibliography of the Algonquian languages, has been published. 

 The sixth will include the languages belonging to the Athapascan 

 stock. The volume on the Algonquian languages contains 2245 

 titular entries, of which 1926 relate to printed books and 

 articles, and 319 to manuscripts. It consists of 614 closely- 

 printed pages, and represents an amount of well-directed labour 

 for which Mr. Pilling deserves the cordial recognition of all who 

 will in any way profit by his researches. 



The atomic weight of copper has been redetermined by Dr. 

 Richards, and an account of his work will be found in two 

 papers contributed to the new Zeitschrift fiir Anorganische 

 Chemie (pp. 150 and 187), From the results of experiments 

 concerning the replacement of silver in silver nitrate by metallic 

 copper. Dr. Richards was led to believe that the number usually 

 accepted for copper, 63*3, was considerably too low. He has, 

 therefore, thoroughly investigated the methods by which the 

 old number was obtained, and made a new series of determina- 

 tions, in which corrections have been applied for the errors due 

 to the mode of analysis adopted. In the year 1874 Hampe 

 made two series of determinations of the atomic weight of this 

 element. One of these, in which the amount of metallic copper 

 contained in copper oxide was estimated, gave the value 63 -34 ; 

 the second, which depended upon the copper content of 

 anhydrous copper sulphate, yielded the number 63 "32. The 

 lower of these values has since been generally accepted as re- 

 presenting most probably the true atomic weight of copper, on 

 account of the extreme manipulative care taken by Hampe, and 

 the remarkable agreement of the individual experiments. Dr. 

 Richards, however, has discovered a flaw in the method. 

 Hampe dried his sulphate of copper at 250° ; but Dr. Richards 

 has experimentally proved that the so-called anhydrous 

 sulphate obtained at this temperature loses about o'i7 per 

 cent, of its weight when heated to the temperature of the 

 vapour of boiling mercury. This loss, moreover, when 

 taken into account in calculating the atomic weight, 

 brings up the figure almost exactly to that indicated by 

 the replacement of silver experiments. An exhaustive investi- 

 gation has eventually shown that copper sulphate retains o'i2 

 per cent, of its water of crystallization, even after it has been 

 subjected to a temperature of 400°. Indeed, this last trace of 

 water is only eliminated at a temperature at which the sulphate itself 

 commences to decompose. Dr. Richards has therefore made a 

 series of redeterminations of the atomic weight by Hampe's 

 method, drying the salt at 25o°-270°. On calculating directly 

 from the figures obtained, the experiments gave the mean value 

 63 "35. a result almost identical with that of Hampe. But upon 

 applying the correction for the slight amount of water still re- 

 tained at this temperature the mean value is raised to 63-60. 



In the second communication Dr. Richards discusses the 

 mode of determining the atomic weight by ascertaining the 

 amount of copper contained in copper oxide. He shows that 

 copper oxide which is prepared by the method employed by 

 Hampe, ignition of the oxynitrate, contains four or five times 

 its volume of occluded gases, and that even at a bright red heat 

 NO. II 80, VOL. 46I 



only a portion of this occluded gas can be expelled. Dr. 

 Richards has therefore made a series of redeterminations by this 

 method, applying the necessary correction for occluded gas, the 

 correction having been very accurately ascertained from a large 

 number of observations. The final mean value of the atomic 

 weight of copper afforded by the whole of Dr. Richards's experi- 

 ments is 63-604 (oxygen = 16), the maximum and minimum 

 values being 63-609 and 63-600 respectively. If the value of 

 oxygen is taken as 15-96, that of copper becomes 63-44. 



The additions to the Zoological Society's Gardens during the 

 past week include two Four-horned Antelopes {Tetraceros 

 qttadricorm's $ ? ) from India, presented by Mr. H. M. 

 Phipson, C.M.Z.S. ; a Huanaco {Lama huanacos <J) from 

 Bolivia, presented by Mr. Frank Parish, F.Z.S. ; a Black- 

 necked Hare [Leptis nigricoUis) from Ceylon, presented by Mr. 

 T. C. Kellock ; a Common Squirrel {Sciurus vulgaris), British, 

 presented by Miss Ruxton ; a Masked Parrakeet {Pyrrhulopsis 

 personata) from the Fiji Islands, presented by Mr. A. B. Holds- 

 worth ; a Booted Eagle {Nisa'etus pennatus), European, pre- 

 sented by Lieutenant J. E. Rhodes ; a Kestrel ( Timtunculus 

 alatidariHs), British, presented by Mr. Frank Allen ; a European 

 Pond Tortoise [Emys europcea), European, presented by Miss 

 Lilian Powell ; two Alligators {Alligator mississippicnsis, jv.) 

 from Florida, presented by Mr. R. White ; a Moloch Lizard 

 {Moloch horridus) from Australia, presented by Mr. John 

 McLey ; a Llama (Z.awa peruana i) fro.m Peru, an Ostrich 

 {Struthio camelus i) from Africa, a One-wattled Cassowary 

 {Casuarius uniappendiculatui), a Common Crowned Pigeon 

 {Goura coronata i ) from New Guinea, two Victoria Crowned 

 Pigeons {Goura victoria <J 9 ), from the Island of Jobie, two 

 Narrow-barred Pigeons {Macropygia leptogrammica) from Java, 

 two Pale-headed Parrakeets {Platycercus pallidiceps) from Norlh- 

 East Australia, two Roseate Spoonbills {Platalea ajaja) from 

 South America, two Vociferous Sea Eagles {Haliaetus vocifer\ 

 from West Africa, purchased; a Japanese YyQG.x {Cervus sika), 

 born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



Light- Variations of Y Cygni.— The British Astrono- 

 mical Journal, No. 266, contains two contributions from Mr. S. 

 Yendell and Prof. Duner, the former "On some observed 

 minima of Y Cygni," and the latter " On the chief cause of the 

 anomalies in the light-variations of Y Cygni." Mr. Yendell in 

 his paper thoroughly agrees with the explanation put forward 

 by Prof. Duner to account for the anomalies in the light-varia- 

 tions, and says that, when the two series of observations are 

 taken simultaneously, "the substantial correctness of his 

 (Duner's) fundamental assumption appears to me to be proved 

 beyond the possibility of a cavil." It may be remembered that, 

 in Prof. Duner's former paper on this subject, he was struck 

 with the discordance of some of Mr. Yendell's observations, 

 which did not seem to harmonize with his own suggested ex- 

 planation. These observations are now published in detail in 

 this paper, and will be read with interest by those who are 

 following up this curious variable. 



Prof. Duner, in a few words, discusses the results obtained 

 when his own observations are compared with those of 

 Mr. Yendell. The differences between the observed and 

 calculated times of minima showed a decided rate of change, 

 the mean rate being -o-023d., but lacked regularity. In 

 one case the jump from one epoch to another amounted 

 to a rate of — o-056d., but he thinks that this may be ac- 

 counted for by a variation in Mr. Yendell's method of observ- 

 ing, for other observations show altogether nearly constant 

 deviations; indeed, "it will be more correct to attribute the 

 discordance simply to errors of observation, than to anomalies in 

 the light-variations of the star." 



Active Lunar Volcanoes ?— Prof. Pickering, in the 

 Observatory for this month, raises the question of active lunar 

 volcanoes, from some recent observations made with the 13-inch 

 Clark, using powers varying from 800-1200. Examining first 

 the Mare Serenitatis, of 67 craters 32 were found common to 



