78 ABSOLUTE ATOMIC WEIGHT. 



Hence we can assert with absolute certainty that the three 

 determinations of Berzelius made by reducing lead oxide by 

 hydrogen, conform to the full limit of the precision of his 

 work to the standard atomic weight of lead, Pb = 207. 



The deviation of the mean is only 2 low (in the fifth 

 place) and the individual determinations fall on either side, 

 two being 8 and 7 low, one being 10 high (in the fifth place). 



These dry way determinations of Berzelius, published in 

 1810 and 1812, in the very beginning of any atomic weight 

 determinations, fix the value of the atomic weight of lead at 

 207, within a very few hundredths as a barely possible un- 

 certainty. 



This is the record of our Science. Here we have the 

 earliest record of the work done by the greatest master in 

 chemistry. Every true chemist should be proud of this 

 record* 



Clarke Falsifying the Record of Berzelius. 



It is therefore with inexpressible disgust and contempt 

 that I read, at the very opening of the report on the atomic 

 weight of lead, in the Smithsonian publication of the Chief 

 Chemist Clarke (Constants of Nature, Washington, 1897) at 

 the top of page 127, the following which, every reader of the 

 historic facts just given will recognize as barefaced and 

 absolute falsehoods : 



"The researches of Berzelius upon the carbonate and 

 " various organic salts need not noiv be considered, nor is it 

 li "worth while to take into account any ivork of his done before 

 " the year 1818." 



The work of Berzelius on Lead Carbonate came within 3 

 units in the fifth place. This dry way work on the oxide 

 came within 2 units of the fifth place of our atomic ratio. 



In both cases this means the determination of the atomic 

 weight of lead to be 207 within a possible range of only 

 three hundredths of a unit. 



At the close of his chapter on lead, this same Chief 

 Chemist Clarke states the result of all subsequent work on 

 lead to run, in the mean values over t~Mo and one half units. 



