GItGmldry of To-day. xv 



Mctual en-or. The recognition of this fact has led, of late, to 

 i-enewecl attempts to determine, by experiments of the most 

 accurate kind, the precise value of this ratio O : H. Among 

 the workers in this field during the past year or two, may 

 be specially mentioned Scott and Lord Rayleigh in England, 

 Crafts in France, Keiser, Cooke and Richards in America 

 The results of these and other experiments may be summed 

 up in the statement that, the value § is between 1601 and 

 15-869 ; and that the atomic weight of uranium (where the 

 consequent error is necessarily greatest) is between 239'76 

 and 237'65. We must look to the future for further light. 



A glance at the table of the elements, arranged according 

 to the periodic law, shows it is far from complete. Many of 

 the elements whose existence is indicated by the law are 

 not actuall}^ known to exist. They have never yet been met 

 with. Is this from lack of knowledge merely, or do the 

 gaps occur in Nature ? When this arrangement was first 

 made use of, it was necessary to leave gaps where now we 

 see the names of gallium, scandium, and germanium. May 

 we not also expect the others to be filled up in a simihir 

 manner? Here is one below manganese, between molyb- 

 denum and the palladium metals, which wants filling by an 

 element with an atomic weight of 99 or 100 and properties 

 that might be fairly well pre-calculated. The most recent 

 chemical journals that have reached us here in Melbourne, 

 contain a brief preliminary notice of some results which 

 Professor Krliss, of Munich, claims to have obtained in an 

 investigation of cobalt and nickel. These elements have 

 always been rather an enigma, from the fact of their 

 possessing, not only very closely similar properties, but an 

 almost identical atomic weight ; and our great English 

 chemist, Crookes, has even said of them, that they might 

 have been still regarded as one and the same element, had 

 only their salts possessed the same colour instead of colours 

 which are approximately complementary. Professor Kriiss 

 now claims to have resolved the old cobalt and the old 

 nickel each into two elements, one of which is common to 



