GENERAL INTRODUCTION*. 



carried, will be shown when we come to examine the Con- 

 stants of Nature published by the Smithsonian Institution. 



We shall incidentally also be compelled to show, that 

 under Moissan this method has finally found its way into the 

 most renowned Chemical Laboratory of Paris and this fact 

 is specially pointed out in a formal report of the entire 

 Chemical Section of the Academy of Sciences of Paris, 

 which granted a prize in accordance with this report, in 

 December, 1900 when as a matter of fact even the simple 

 formula for this calculation is not known in that Laboratory, 

 so that all values calculated are fifty per cent too high! 



We shall therefore have to show this calculation in detail, 

 by applying it to our weighings of the silver dollars. 



The Constant Errors. 



We shall then also see clearly that this method does not 

 furnish any clew to the limit of the constant errors of the 

 chemical work, or any indication of the real error com- 

 mitted in which opinion chemists have used it but simply 

 gives mathematical expression of the degree of concordance 

 of the experimental determinations made. 



It would indeed be delightful to possess some mathe- 

 matical process by which erroneous chemical work could be 

 corrected. 



Chemists evidently thought that the calculation of the 

 probable error shows them at least how near they came to 

 the truth. 



That this absurd fallacy could become accepted so widely 

 in the chemical world is very deplorable; but that chemists, 

 like Moissan, do not even take the trouble to use the true 

 formula, is almost incredible; unhappily it is true 



Two Common Errors. 



We shall next find, that two additional and very grave 

 errors are commonly committed in the so-called reductions 

 of experiments or observations by chemists and other sci- 

 entists, and which errors must be avoided to obtain true 

 results of atomic weights. 



