THE PEUIODW LAW. i59 



somewhat after the method of Newlands, but this table could be con- 

 sidered in no sense an advance upon the table of his English contem- 

 porary. It was not so much a periodic table as a summary of the 

 groiiping of the elements in more or less natural groups. Meyer, 

 indeed, made his earlier table the basis of his later work, but these 

 subsequent amendments to the table were made after the publication 

 of Mendeleeff's first table and show clearly the influence of his work. 



In his first paper, Mendeleefl; gives several different arrangements 

 of the elements, all, however, embodying the same principles. The 

 principal table, of which the others are variants, shows many errors 

 and crudities, but the underlying principles of the Periodic Law, as 

 to-day recognized, are clearly apparent. This table is as follows: 



MENDELEKFF'S FIRST TABLE. 1809. 



Ti 50 Zr.... 90 ? ... .180 



V 51 Nb... 94 Ta...l82 



Or 52 Mo.. 96 W....188 



Mn 65 Rh.. .104.4 Pt....l97.4 



Fe 56 RU..104.4 Ir....l98 



Ni,Co..59 Pd...l06.6 03... 199 



H 1 Cu 634 Ag...l08 Hg..200 



Be... 9.4 Mg...24 Zn......65.2 Cd...ll2 



B 11 Al 27.4 ? 68 Ur...ll6 Au..l97 



C 12 Si 28 ? 70 Sn ...118 



N 14 P 31 As 75 Sb...l22 Bi....210 



16 S 32 Se 79.4 Te....l28? 



F 19 01. ...35.5 Br 80 1 127 



Na 23 K 39 Kb 85.4 C3...133 T1....204 



Ca....40 Sr 87.6 Ba...l37 Pb...207 



? 45 Ce 92 



?Er..56 La 94 



?Y .. 60 Di 95 



?In...75.6 Th 118 



The resemblance to the modern tables comes out yet more strongly 

 when we examine Mendeleefli's horizontal table, which was published 

 in the same paper, and in which the doubtful elements and those whose 

 position was not clear were omitted: 



MENDELEEFF'S HORIZONTAL TABLE. 1868. 



In the first table the elements are arranged in vertical columns, in 

 the order of their atomic weights. They fall in a way into groups of 

 seven, as in Newlands's octaves, but after the first two octaves there 



