ERRORS OF WEIGHING. 43 



In other words, the chemical work of Berzelius, probably 

 effected by means of a good centigramme balance, is fully as 

 accurate, chemically speaking, as the most pretentious weigh- 

 ings cm record made to the ten-millionth of the gramme, 

 by Ramsay and Aston in 1893, using one of the finest 

 balances ever made and supplying the fine weights by calcu- 

 lating from the oscillations of the pointer over the scale. 



We shall learn, after a little, that Berzelius really got 

 nearer the truth with his centigramme balance than did 

 Ramsay with his balance one hundred thousand times more 

 sensitive (at least on the record printed) than the balance of 

 Berzelius. 



Great Chemist, Poor Balance. 



If we were given to calculating the "weight" of the 

 work done by chemists, as is customary at Washington, 

 what would be the comparative value of these chemists? 



The " weight " of determinations varying inversely as the 

 " square" of the " errors/' it would follow that Berzelius was 

 in 1826, a 10,000,000,000 times better chemist as Ramsay 

 in 1893. 



But it is well understood that we do not indulge in such 

 calculations. They belong to the scientific departments at & (fat &*/&>* 

 Washington. However, this result remains: Berzelius came 

 nearer the truth with his simple means than did Ramsay 

 with all the refinement of modern science. 



What then is the real chemical lesson which we should 

 learn from this remarkable incident put on record in all 

 works on atomic weight determinations though, perhaps, 

 not brought out quite as strikingly. 



The real errors committed by Ramsay and Aston in this 

 work were : 



First, giving a fictitious degree of accuracy at least two 

 decimals too many. 



Second, using a balance much too fine for the chemical 

 work to be done. 



Third, they did not realize that the finest weighing 

 cannot possibly compensate for the lack of purity of sub- 

 stance or the absence of perfection in the chemical operation. 



