ERRORS IX PRECISION*. 29 



claimed as the atomic weight determined often by great 

 skill and patience in the chemical laboratory. 



The Two Fatal Common Errors. 



First, the chemist will calculate the atomic weight with 

 two or even more decimals, when a simple examination 

 would have convinced him that these decimals have abso- 

 lutely no value whatever, being far beyond the limit of 

 precision of his chemical work. 



Second, the chemist will start in this calculation with 

 the data of one of the national leaders of organizations, and 

 if these data are wrong (as we shall find them to be) he will 

 necessarily get erroneous values from the very best laboratory 

 work he can produce. 



It is very unpleasant to make such sweeping statements; 

 but it is not our fault that these statements are an exact rep- 

 resentation of the actual facts. 



And if the reader for a moment will free his miud from 

 the power of authority whether it be of numbers, name or 

 station, he will see the necessity of the full recognition of 

 this state of facts in order to clear the way to obtain true 

 results from good chemical work. 



Don't give us your Fancy for Fact. 



First, we must demand that no chemist publish to the 

 world an atomic weight as representing his laboratory work, 

 his chemical research of precision, when, as a matter of fact, 

 he gives decimals that have no foundation whatever in his 

 chemical determination and weighings, but simply are 

 products of his own imagination. 



That which is common practice in the Laboratory of 

 Moissan of Paris, presented by him to the Academy of 

 Sciences of Paris, and recommended by the present Section 

 of Chemistry of that Academy for the Prize Vaillant which 

 was granted by the Academy in December last, cannot be a 

 special sin when committed in an American Laboratory and 

 published in our Journals of Chemistry. I refer to the work 

 of Henry Gautier on boron, in the Laboratory of Moissan. 



