/. W. Mallet on the Atomic Weight of Lithium. 349 



Thus, then, the continent was completed. Contraction was 

 the power, under Divine direction, which led to the oscillations 

 of the crust, the varied successions in the strata, and the exuvia- 

 tions of the earth's life, era after era. Acting from the Atlantic 

 and Pacific directions, it caused the southern prolongation of the 

 growing land from the icy North to the tropics, while it raised 

 mountains on the borders, and helped to spread the interior with 

 plains, varied slopes, and lakes. And, finally, through its action 

 over the north, the surface received its last touches, fitting it 

 for a new age — the Age of Mind. 



Art. XXVI. — Re-determination of the Atomic Weight of Lithium ; 

 by J. W. Mallet, Ph.D. ; Professor of Chemistry, Univ. of 

 Alabama. 



Lithium is one of the elements whose atomic weight has 

 been several times made the subject of investigation by different 

 chemists, and yet on examining the results of their labors we 

 find that but one or two experiments free from serious objection 

 are recorded, from which the received equivalent number of the 

 metal has been calculated ; and even in these experiments the 

 method pursued has not, I believe, been such as to ensure the 

 closest approximation to the truth. Yet the formulae of the salts 

 of lithia, and of minerals containing this alkali, would be seri- 

 ously affected by any considerable error as regards the equiva- 

 lent number assumed, since this is one of the very lowest to be 

 found in the whole list of elements — the lowest among the 

 metals, with the single exception of glucinum. The fact that 

 Lithium does possess so small an atomic weight — a fact which 

 is said to have led to the discovery of the metal by Arfwedson— 

 is in itself very remarkable when we remember the much higher 

 numbers by which the other alkaline metals, potassium and 

 sodium, are represented ; and it gives additional interest to accu- 

 rate experiments made for the purpose of fixing the number 

 with precision. 



The following historical notice of what has been already done 

 in this direction I have taken from a valuable little work by 



the latter,) was gradually evolved, until winter had settled about the poles as well 

 as the earth's loftier summits, leaving only a limited zone, — and that with many 

 variations, — to perpetual summer. 



The organic history of the earth, from its primal simplicity to the final diversity, 

 is well known to exemplify in many ways the same great principle. 



Thus the Earth's features and functions were successively individualized : — first, 

 the more fundamental qualities being evolved, and finally those myriad details in 

 which its special characteristics, its magnificent perfection, and its great purpose of 

 existence and fitness for duty, largely consist. 



