Nov. 13, 1884] 



NA TURE 



45 



IooPbSOj yield 109-24+4 PbN 3 O = b 



109-307 ,, Turner 



lOoPb ,, I59'9S 



i59"9743 ■• Stas 



looPbN,0 6 = b ,, 67-3799 PbO = 1 



67 40 1 6 ,, Svanberg 



LoAgClmrrespond^ 2r56o7 U C\ = l - 



29*584 ,, Mallet, Troost 

 39-2692 



39'3SS 



62 -650s LiN 3 O i; = c 



iooAg con 



b 

 Stas 



yield 



162-5953 „ Stas 

 130-38960 TIN ,1 i, ; 



Crookes 



Nilson and Pettersson 



Svanberg & Nordenfeldt 

 Marchand and Scheere 



100TI yield 

 Experiment S .. 130-3897 , 



Mean of 10 experi- \ 



ments J J Jy ' 



tooG 3 O s (Sl » 3 ) 3 .I2H0 - c contain— 

 14.1694 GO 

 14-169 ,, 



tpoMgC s 4 H : 2 = < contain — 



27-338 MgO 

 -^7-3665 „ 

 1 ooMgCO :! = <- contain 476 ,, 



Mean of 19 experi- \ dro , 7 



ments J 4/ ' " 



IO0H4N3.SO4.3AIOSO3.24HO = cb contain— 

 11-2814 A10 

 Mean of 10 experi- \ MU 



ments J " J " 



looH4N t S04.3GaOS0 3 .24HO = cb contain— 

 18-9325 GaO 

 18-9596 ,, Lecoq de Boisbaudran 



These determinations include the most classical labours on 

 record, and the general agreement with the calculated numbers 

 is surprising, and the more conspicuous in the cases in which the 

 efforts of the experimenters to exclude error have been pushed 

 to the utmost limits, as in Stas's syntheses and in Prof. Crookes's 

 synthesis of thallium nitrate. Notwithstanding the difficulty in 

 this case, because the element is the heaviest of all so far dis- 

 covered, one experiment has yielded the identical calculated 

 number, and the mean of all deviates from it only by 0-00131. 

 Moreover the same weights recur in similar compounds ; all 

 nitrates, for instance, have a lower value than the corresponding 

 chlorides and sulphates, and the value is the lower the greater 

 the composition, as in the alums. The evidence is such that no 

 doubt seems to be admissible as to the reality of a variation of 

 the atomic weights. This conclusion is independent of any value 

 of the atomic weights ; for the discrepancies exhibited in the 

 results of Prof. Clarke's recalculations from the same experi- 

 mental data above quoted are inevitable if the variation of the 

 atomic weights is not taken into account. In c units Ag is 

 108-09679 if H = I, calculated from the weights of column t ; 

 CI in the gaseous state is = 35 '66 ; the calculated weights corre- 

 spond therefore, within the limits of experimental errors, to the 

 atomic, but the weights are those of different states. 



The difference between the weights of the gaseous and the 

 other states is very considerable ; the weight of 3 molecules of 

 Il,X,I.IIgI, for instance, is = 378 in the state of gas, 354-734 

 in / units, 352-847 in units = c ; the discrepancies are so great 

 that they exceed by far the limits of possible errors, and as from 

 the comparisons made it appears certain that the different values 

 are realities, the only explanation is that the atomic weights 

 vary. If in new experiments, in which the possibility of varia- 

 tion is kept in view, all discrepancies which actually exist should 

 disappear, variation will be established beyond all doubt. It 

 will then be in order to inquire into its cause. How the weights 

 of the tabic have been obtained is, for the present, unessential ; 

 it is only necessary to add that column v contains Prof. Clarke's 

 recalculated weights, and column u the same values calculated 

 from the weights of column I, column x giving the number of 

 atoms represented in each instance. Column -a> shows the corre- 

 sponding weights of the gaseous state. These columns have 

 been added for the sake of comparison. 



Li ... 



Ca ... 



Na ... 

 K 



Kb ... 



Mg ... 



Sr ... 



Ba ... 



Pb ... 



Ag ... 



Cs ... 



H ... 



N ... 

 O 

 F 



CI ... 



Br ... 

 I 



B 

 G 

 C 



Si .. 



Al .. 

 P 



Ti .. 

 La 

 S 



Di .. 



Yt .. 



Yb .. 



Ce .. 



Sc .. 



Zr .. 



Ga .. 



As .. 

 V 



Cr .. 



Mn . 



Fe .. 



Ni .. 



Co .. 



Sn .. 



Cu .. 



Nb .. 



Zn .. 



Ta .. 



Se .. 



Sb .. 



W .. 



Mo .. 



Cd .. 



In .. 



Th .. 

 U 



Te .. 



Au .. 



Bi .. 



Ir .. 



Pt .. 



Hg .. 



Os .. 



Ru .. 



Rh .. 



Pd .. 



Tl .. 



2-36559 

 6-23656 

 7-52688 

 12-68817 

 27-5269 

 3-8537 

 4-I303 

 20-05183 

 32-7566 

 34-683467 

 42-605 

 0-31915 

 1 -48936 



2 -553l9 

 6-04166 

 11145S3 

 25-3125 

 40-3125 

 I-I4583 

 I-45S33 

 1-875 

 2-29166 

 2-9166 

 3-3333 

 4-375 

 4-5833 

 5 



5-20833 

 6-25 

 6-45833 

 6-6666 

 6-875 

 7-oS33 

 7-5 



7-9166 

 8-125 



875 

 S-95S3 

 9-375 

 9-4792 

 9-5833 

 10 



10-20833 

 10-4166 

 11-04166 

 12-5 

 13-125 

 14-79166 

 15-625 

 1770S3 

 1 S '3333 

 18-54166 

 19-1666 

 20-4166 

 21-25 

 22-5 

 31-25 

 31-6666 

 31-875 

 32-0833 

 33-I25 

 33-3333 

 33-95S33 

 64-375 



7-412 

 39-0824 

 23-5842 

 39-7564 

 86-2424 

 24-15 

 88-5498 

 138-1915 

 205-2748 

 108 -674s 

 i33'496 

 1 



14 

 16 



iS-93 

 34-9236 

 79-3125 

 126-313 

 10-771 

 9-072 



"■75 



2S722 



27-416 



31-33 



54'833 



143-61 

 31-33 



146-875 

 88-125 



182-125 



139-26 

 43-0833 

 88-7777 

 7o-5 

 74-4I7 

 50-9166 

 52-222 

 54-S33 

 56-I39 

 58-75 

 59-403 



I20-II 



62-666 



95-95833 



65-278 

 184-5186 



7S-333 

 I23-375 

 185-3888 



97-9166 

 110-972 

 114-888 

 232-389 

 240-222 



27-945 



99'75 

 211-5 

 I95-833 

 198-444 



19975 



201-056 



103-7916 



104-444 



106-403 



201 70S 



7-0235 

 40'oS2 

 23-051 

 39-109 

 85-529 

 24-014 



87-575 

 37-007 

 206-946 

 107-923 

 [32-918 



I -0023 

 14-029 

 16 



19-027 

 35-45I 

 79 '95> 

 126S48 

 10-966 

 9-106 



12'OOH 



28-26 



27-075 



3I-029 



49-961 



138-844 

 32-058 



144-906 

 90-023 



I73-I58 



140-747 

 44'o8l 



89-573 

 68-963 

 75-09 

 51-373 

 52-i29 

 54-029 

 56-042 

 58-062 

 59-023 

 II7-968 

 63-3I8 

 94-027 

 65-054 

 182-562 

 78-978 

 I20-23I 

 184-032 

 95-747 

 II2-092 

 II3-659 

 233-95I 

 239-03 

 I2S-254 

 ! • 1 -( n id 



208 -oo I 



193-094 

 194-867 



200-171 



198-951 

 104-457 



104-285 

 105-981 

 204-183 



7-333 

 38-666 



23-333 

 39-333 

 85-333 

 24 



88 



37-333 

 204 

 108 

 132-666 



I9-333 

 35-666 



12 



32 



56 

 146-666 30 



32 

 150 



90 



66-666 

 188-444 



So 

 126 



I89-333 

 100 



1 13 - 333 

 "7-333 

 237j33 



■45"333 



30-666 

 204 

 216 

 200 



202 -666 

 204 



205-333 

 106 



1 06 666 

 1 08 -666 

 206 



12 



6 

 27 

 13*5 



27 

 142-222 20 



44 6 



90-666 



72 



76 



52 



53-333 



56 



57-333 



60 



60-666 

 122-666 



64 



San I* ranctcco, California July ".4 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



Cambridge. — The following gentlemen were on Monday, 

 November 3, elected to Fellowships at St. John's College :— 

 C. M. Stewart, M.A., First Class in Natural Sciences Tripos of 

 1879, author of several papers on chemical subjects, and Master 



