118 COMBINING PROPORTIONS. 



The consideration of the laws of Wenzel and Richter, which 

 were long overlooked or misunderstood, was revived by him, 

 and by a series of analytical researches unrivalled for their ex- 

 tent and accuracy he first impressed upon chemistry the cha- 

 racter of a science of number and quantity, which is now its 

 highest recommendation. Several of Berzelius's numbers 

 received a valuable confirmation from Dr. Turner, whose in- 

 quiries were especially directed to test an hypothesis respecting 

 them, advocated by some of his contemporaries ; namely, that 

 the equivalents of all the elements are multiples of the equiva- 

 lent of hydrogen, and consequently if that equivalent be made 

 equal to 1, all the others will be whole numbers. Dr. Turner's 

 results are incompatible with such a relation among the equiva- 

 lent numbers, the existence of which indeed is disproved by all 

 accurate analyses.* 



Still the existence of a simple relation between certain equi- 

 valents has been pointed out by M. Dumas ; and it is possible 

 that the numbers of each of the pairs below, which approach 

 so closely, would actually coincide, as they do in one pair, 

 were they determined with absolute accuracy. 



Platinum . . 1233.5 



Iridium . . . 1233.5 



Sulphur . . . 201.17 



. Tellurium. . 200.44 



Cobalt . . . 368.99 

 Nickel . . . 369.68 



Osmium . . . 1244.49 

 JEq. Gold . 1243.01 



But these are the only equivalents between which there are 

 good grounds for supposing that any relation exists, The 

 identity of the atomic weights of platinum and iridium is the 

 most certain, having been experimentally confirmed by Berze- 

 lius since it was first asserted by Dumas. 



Of the two series of numbers given in the tables, the 

 first in which oxygen is made equal to 100, and which is 

 called the oxygen series, is the most convenient, and will 

 alone be made use of in the following pages. The numbers of 

 this series are so large that the fractional portion may, I believe, 

 be safely neglected in computing by them, being within the 

 unavoidable errors of observation in chemical analyses, and the 

 nearest whole number may be adopted, except in the following 

 equivalents, although even in them it is unnecessary to go be- 

 yond the first decimal figure : 



* Philosophical Transactions, 1833, p. 523. 



