July 21, 1881] 



NATURE 



277 



difference, the law of proportionality being thus still observed. 

 Now taking the simple arithmetical progression having for 

 difference t = 3, 1416, it furnished a series of terms which 

 markedly concord with the series of the atomic weights or 

 equivalents as presented by Mendeleefif's Tables, ai.d the succes- 

 sive blanVs occurring in the series established by him in his 

 Tables are very approximately hlled up by the succession of the 

 terms of this progression both as regards numerical values and 

 order of succession. 



To demonstrate thi^ Mendeleeff's Tables have been drawn out, 

 with the addition opposite each equivalent of the corresponding 

 approximate value m terms of the progression tt. 



In Table I., containing his grouping into jypical and Great 

 Pii'iods, there is shown the succession of the elementary bodies 

 and their equivalents, as also the comparative concordant succes- 

 sion of the terms of the progression tt with approximate values 

 mostly in terms of j ir. 



In the Table Ii., or ai Periodic Series, the blanks existing in 

 these series as indicated by MendeleeH are shown to be very 

 approximately filled up by corresponding terms, in value and 

 order of succession, of the progression t. This is markedly the 

 case as regards the gap existing between the series S and 10, 

 where are wanting twelve terms, which, being filled up by suc- 

 cessive terms of the progression ir, the thirteenth term, corre- 

 sponding to the equivalent of I.amhaimm = 180 (?) is represented 

 in the progression -n by the value 57j»^ — 180, 1164, or approxi- 

 matively by the value 57'r = 179, 0712. 



Considering this progression of terms of jr it will be found that 

 of the sixty-five elementary bodies given in Mendeleeff's Tables 

 the following corresponding equivalents are represented, with an 

 aiiproximation of less than a unit, by terms of the progression : — 



H = 1 ... iir = I, 0472 



Be = 9. 4 ■■• S'^ = 9. 4248 



C = 12 ... 4ir=I2, 5664 



O =16 ... 5 ir = 15, 70S0 



Fl = 19 ... 6 7r = IS, S496 



Si = 28 ... 9 TT = 28, 2744 



Ph = 31 ... lOTT = 31, 4159 



Ca = 40 ... 13 ir = 40, 8404 



Ta = 48? ... 15 7r = 47, 1240 



Va = 51 ... lb T! -- 50, 2656 



Fe = 56 ... iS TT =; 56, 548S 



Ni = 59 ... 19 T = 59, 6904 



Co = 59 



Cu = 63 ... 20 7r = 62, 8313 



Zn = 65 ... 21 IT = 65, 9736 



(Gallium? = 691 ... 22 TT = 69, 1150) 



(Norwegium? = 72 ... 23 ir = 72, 2566) 



As = 75 ... 24 ir = 75, 39S4 



Se = 78 ... 25 IT = 78, 5400 



Rb = 85 ... 27 T = 84, 8232 



Yt = 88 ... 28 IT = 87, 9648 



Zr = 90 ... 29 TT = 91, 1064 



Nb = 94 ... 30 7r = 94, 2477 



(Terbium? = 99 ... 32 ir = 100, 5312) 



Ru = 104 ... iZ-^ = 103, 6725 



Rh = 104 ... ,, ,, 



Pd = 106 ... 34 T = 106, S144 



In = 113 ... 36 7r = 113, 0976 



Sb = 122 ... 39 T = 122, 5224 



Te = 125 ... 40 TT = 125, 6636 



Cs = 133 ... 42 T = 131, 9472 



Di = 138? ... 44 T = 138, 2300 



Ce = 140-141 ... 45 T = 141, 3720 



pavyum? = 153 ... 49 7r = 153, 9384\ 



vDecipium? = 157 ... SO'r = 157, 0795/ 



Er = 178 ? ) 



La = .So?! - 57 -= •79, 07.2 



Ta = 182 ... 58ir = 1S2, 2128 



Os = 195 ... 62 TT = 194, 7786 



Pt = I98 I ••• ^i'' = '97. 9208 



Hg = 200 ... 64 TT = 201, 0624 



Tl = 204 ... 65 IT = 204, 2040 



Pb = 207 ... 65 TT = 207, 3450 



Such a concordance must be taken as some proof of the reality 

 of a certain correspondence between the values of the equivalents 

 and those of the terms of the progression r. 



It is fully admitted that the equivalents are but relative, both 



as regards their number and their numerical values, to the forces 

 which the present state of chemical analysis can bring to bear on 

 matter, and admitting the existence of a law of progression by 

 which the equivalents may be connected, such a ]irogres-ion 

 should as a matter of necessity differ both as regards the number 

 of representative terms and their valnes from the pre-ent received 

 succession and numerical values of the equivalents, and conse- 

 quently show discordances iu certain places and approximate 

 concordances in others ; such is shown by the terms of the pro- 

 gression n. J. P. O'Reilly 

 May, 1880 



B/J^DS OF THE SOLOMON ISLANDS 



TN a paper " On the Birds of the Sol mon Islands," by E. P. 



Ramsay, F.L.S., &c.. Curator of the Au.stralian Museum, 



Sydney, read before the Linnean Society of New South Wales, 



February 23, 18S1, the following new birds were described : — 



1. Grancalus elegans, sp. uov. — A species allied lo G. hypo- 

 leitcus of Gould, but differing in its smaller size, whiter under- 

 surface, broad jet black band on lorcal region, extending below 

 the eye, and in having ashy grey shoulders. 



2. Piczorhyiichits Kieliardsii, sp. nov. — A remarkably distinct 

 species, with the body and the wings and tail above black, 

 ossified nape, and hind ueck white, head and throat black, chest 

 and remainder of the under surface chestnut ; this species comes 

 from the Island of Xyi, and has been named in c impliment to 

 Lieut. Richards, R.N. 



3. Myzomela Tristranii, sp. nov. — A jet black myzomela of 

 large size, the bill strong and yellow, with end blact, bases of 

 the inner webs of the quills below ashy. This species is allied 

 to, but distinct from, M. nigra, M. Forbesii, and M. pain- 

 melana. 



4. Afygomela pidcherrima, sp. nov. — This fine species has the 

 whole of the head, neck, chest, breast, and sides of the body 

 and flanks, the interscapular region, rump, and upper tail coverts 

 of a rich deep crimson, the remainder of the plumage black. 

 The extent of the scarlet on the flanks and breast is greater than 

 in either of the allied species M. cardinalis and M. nigriventris. 



5. Zostcrops {Tep/iras?) olivaceiis, sp. nov. — In this genus 

 there is no trace of white round the eye, and the bill has quite a 

 diflerent contour than that of any species of the genus Zosterops. 

 The first and sixth primary quills in this species are equal, and 

 the third is equal in length to the fourth. The general colour 

 above is a uniform dull brown w,ished with olive, inclining to 

 smokey brown on the head, inner webs of the quills below mar- 

 gined «ith white, under surface light ashy brown, almost white 

 on the abdomen, length about five inches. 



6. Nasiterna fiuschii, sp. nov. — A very distinct species of a 

 uniform grass-green tint, paler on the abdomen, under tail 

 coverts yellow, length 3"8 inches. 



The paper contains notes on six or eight other species of 

 interest and a fine collection of Solomon Island birds were 

 exhibited — about fifty species. 



OUR ASTRONOMICAL COLUMN 

 The Variable Star x Cvgni. — A maximum of this variable 

 should now be close at hand. Prof. Winnecke assigns it to 

 July 31, rather later than the average peri id of the last few years 

 would give it. Its brightness at maximum has varied during the 

 present century from 4m. to a very little above 701. In vol. vi. 

 of the Bonn Observations, Argelander has given nine observa- 

 tions of the position of this star, about which there has been so 

 much and unnecessary confusion. Its place for i88o'0 is in 

 right ascension igh. 45m. 57'33s., declination 32° 36' 42"'r. A 

 comparison of Lalande's observation in 1793 with Argelander's 

 shows that there is no appreciable jiroper motion. The varia- 

 bility of X Cygni was discovered in 1686 by Kirch, whose first 

 observed maximum is dated November 28, 1687. 



Comet 1881 b. — It appears this comet was detected at Sydney 

 as early as May 22, so that we may yet receive observations from 

 the Australian observatories made nearly a week before the first 

 of tho-e made at Rio Janeiro. The orbit, founded upon post- 

 perihelion places, which we published last week, gives the comet's 

 place on Rlay 22 at 10 p.m. at Sydney in right ascension 

 4h. 58'Sm., declination 35 33' S., and at this time the comet 

 was distant from the earth 0772 of the earth's mean distance 

 from the sun. M. Cruls' first position, deduced from the obser- 

 vations at Rio is as follows : — 



