Nov. 28, 1889] 



NATURE 



^7 



from an exhaustive examination of the record books, will be 

 commenced. In the past year sixty- one sheets were scored 

 under the superintendence of the Trigonometrical Assistant, 

 each representing an area of 13 '6 miles by 8*8 miles, and con- 

 taining in all 1687 fixed stations. He has alsi prepared an 

 elaborate map of the island, showing sheet line distances. 



The Report for the past year on the mining and mineral 

 statistics of Canada, by Mr. H. P. Brumell, of the Dominion 

 Geological Survey, has been received in this country. The 

 total value of the production of minerals of all kinds for the 

 year was $16,500,000 — an increase of 1,500,000 as compared 

 with 1887, and 6,000,000 against 1886. Coal is the largest 

 mineral product of the Dominion, the value of last year's 

 yield amounting to $1,098,610, as against $1,178,637, in 1887, 

 and $1,330,442 in 1886. The decrease in the yield of gold has 

 been anticipated for some years. Copper was mined to the 

 value of $667,543, and these figures will in all probability be 

 doubled this year, in view of the rapid development of the 

 Sudbury and Lake Superior Mines. The asbestos yield 

 amounted to $255,007, and the phosphate production shows 

 an appreciable increase. 



The Smithsonian Institution has issued a " Preliminary Cata- 

 logue of the Shell-bearing Marine Mollusks and Brachiopods 

 of the Snuth-Eastern coast of the United States," by W. Mealey 

 Dall. The volume includes admirable illustrations of many 

 species. 



We have received the sixty-second part of the first division of 

 the " Encyclopjedie der Wissenschaften,"' and the fifty-fourth 

 and fifty-fifth parts of the second division of the same work 

 "(Breslaii, Trewendt). The first of these three parts is a contri- 

 ibution to tlie hand-book of botany included in this En.;yclopa:dia ; 

 ;the second and third conclude the seventh volume of the Encyclo- 

 paedia's Dictionary of Chemistry. 



A NEW series of well crystallized salts, ammoniacal selenites, 

 are described by M. Boutzoureano in the current number of the 

 Attnales de Chimie et de Physique. Most normal selenites are 

 found to be readily solulile in strong ammonia, and the solutions 

 on evaporation either in the-air or i)i vacuo deposit crystals of 

 ammoniacal selenites. Four of these interesting salts have been 

 studied in detail, those of zinc, cadmium, "copper, and silver. 

 Ammoniacal zinc selenite, ZnO. SeOj.NHj. is obtained by dis- 

 solving neutral zinc selenite, ZnO. SeOj, a salt which crystallizes 

 in rhombic prisms, in strong ammonia at the ordinary tempera- 

 ture. On allowing the solution to spontaneously evaporate, 

 crystals of the ammoniacal salt are deposited in the form of fine 

 long prisms capped by domo-prisms belonging to the rhombic 

 system. The crystals are insoluble in water, which appears to 

 exert no action whatever upon them. They are also unchanged 

 by heating to 100° C, but when heated in a sealed tube the 

 selenious oxide is reduced by the hydrogen of the ammonia with 

 evolution of water vapour and sublimation of selenium. On 

 ignition they are completely converted to zinc oxide. Acids 

 readily dissolve the crystals even when largely diluted with 

 water. The constitution of the salt appears to be 



/O 

 Zn<; /N H3. 



\0-Se— 0/ 



Normal cadmium selenite, CdO. SeO.2, is also soluble in am- 

 monia, and the solution leaves on evaporation white rhombic 

 crystals of an ammoniacal cadmium salt, CdO.SeO2.NfI3, 

 analogous to the zinc salt. These crystals are likewise unattacke I 

 by water, and are stable at 100°. They also give off water and 

 ■vapour of selenium when heated in a sealed tube. The most 

 beautiful salt of the series, however, is the ammoniacal copper 

 selenite. Copper forms a normal selenite of the composition 



3(CuO.Se0.2). HgO, which crystallizes in small green monoclinic 

 crystals. These crystals readily dissolve in ammonia, forming a 

 deep bluish-violet solution, which on slow evaporation in the 

 air yields magnificent blue crystals of the ammoniacal salt 

 belonging to the triclinic system. The salt is found to contain 

 one molecule of water, and is represented by the formula 

 CuO.SeO2.NH3. H.2O, the constitution being probably more 

 nearly expressed in the following manner, 



/CuO— on 



H3EN/ 



\Se0-0M 



Unfortunately these fine crystals soon alter in contact with air, 

 losing their water and ammonia and becoming covered with a 

 green coating of basic copper selenite. Water has apparently 

 no action upon them, but in reality there is a surface action, the 

 coating of basic selenite thereby formed preventing any further 

 decomposition. In a similar manner silver is found to form an 

 ammoniacal selenite, the crystals belonging, like those of the 

 copper salt, to the triclinic system. They are anhydrous, 

 Ag2O.SeOo.NH3, and are blackened by exposure to sunlight. 

 Thus the series is seen to be a very well defined one, the mem- 

 bers consisting of normal selenites combined with one molecule 

 of NH3, generally anhydrous, but occasionally, as in case of the 

 copper sa't, containing water of crystallization. 



The additions to the Zoological Society's Gardens during the 

 past week include a Barbary Ape (Macaciis inuus <i ), a Saker 

 Falcon {Falco sacer) from North Africa, presented by Captain 

 Augustus Kent ; a Malbrouck Monkey {Cercopithectis cyno- 

 surus i) from West Africa, presented by Dr. Messiter Lang ; 

 two Fieldfares {Turdtts pilaris), British, presented by Mr. J. 

 Young, F.Z.S. ; a Golden-naped Amazon {Cluysotis atiripal- 

 liata) from Central America, purchased ; a Molucca V>tttx {Ceiinis 

 viohtccensis'), born in the Menagerie. 



OUR ASTRONOMICAL COLUMN. 



Objects for the Spectroscope, 



Sidereal Time at Greenwich at 10 p.m., November 28 

 31m. 57s. 



2h. 



Remarks. 



(i) Sir John Herschel describes this nebula as : Very bright, 

 very large, very much extended, very much brighter in the 

 middle. Dr. Huggins noted, in i865, that the spectrum was 

 continuous, but pointed out in his remarks that this was not to 

 be understood to mean more than that, when the slit was made 

 as narrow as the feeble light permitted, the spectrum was not 

 resolved into bright lines. Farther observations are therefore 

 required, for it may be that slight brightenings in the apparently 

 cmiinuous spectrum were overlooked in the early observations. 

 The case of the nebula in .Andromeda indicates tiiat, in some of 

 the nebulae of this class, bright carbon flutings may be super- 

 posed upon the contitmous s lectrum, in which case they will not 

 be very obvious. The carbon tluings seen in the spectrum of 

 the flame of a spirit-lamp are convenient for comparison in an 

 observation of this nature. 



(2) This is a typical star of Gr nip II. Diiner describes it as 

 superb and brilliantly developed, the bands 1-9 being perfectly 

 visible. The star therefore affords an oi)portunity of observing 

 the bright carbon flutings and checking their positions. If they 



