THE RARE EARTHS. MAGEE. Ixxvii 



be filled in. Whence 1 Undoubtedly in most cases from the rare earths. 

 Ni. and Co. according to Kriiss' work seem to conceal an element which 

 may be found to have an atomic weight of about 100 and the earths 

 conceal many. Within a few years Di. has been split up, one component 

 showing absorption bands and the other failing to do so. As already 

 pointed out, two earths once considered simple have yielded at least 

 twelve and when the means of the separation, when the reagent or 

 method is. finally found, then the vacant spaces will be filled. 



But it is not only that the rare earths will probably fill these vacant 

 spaces in the table that gives them importance, their similarity is such 

 in regard to action towards reagents that they seem to run contrary to 

 the law. If so many of them are of the formula R 2 . 8 , they cannot be 

 distributed over the table but will mass in groups and destroy the table. 

 Of course if the table is incorrect the sooner it is proven the better so 

 that the mind of the inorganic chemist may be directed elsewhere for 

 comparisons, and it is just possible that in this very thing lies the 

 importance. Still the periodic law seems to rest on good foundation. 



The great importance then seems to lie just here. These rare earths 

 exist, of this there can be no doubt. The best chemical skill that the 

 world has possessed have been working upon them for over a century, 

 and have so far been unable to confidently state their number and 

 actual properties. The more work that is put upon them the greater the 

 number of them seems to be. If the ones now claimed are all real there 

 is not room for them in the law, i.e. spaces are wanting for their apparent 

 weight. Until this question can be settled a mystery hangs over this 

 portion of the Periodic system. The unravelling of this may work an 

 entire change in our ideas of the elements. Their subtle resemblances 

 have suggested to me more than once, while pondering over them, that 

 in these lies the key to the simple elements which many chemists 

 believe to be the foundation of the so-called elements. As in the 

 Marsh-gas series the time comes when the Hydrogen-Carbon chain 

 becomes too heavy for the bonds or affinity to sustain the weight, so in 

 our inorganic field something of the same kind may result. The 

 hypothetical elements may in certain numbers of atoms or in certain 

 arrangement of atoms yield such similar properties that the one compound 

 is distinguishable with difficulty from another. Time and high chemical 

 skill alone can unravel the mystery, but so long as things remain as they 

 are there remains an element of uncertainty in the periodic law. We have 

 PROC. & TRANS. N. S. INST. Sci., VOL. X. PROC. H. 



