LEAD. BERZKLIUS. 89 



wav of chemistry, and defrauding his subscribers, as is 

 Mr. Wm. Crookes, Chemical News, vol. 73, p. 231 ; 1896. 



The eighth reaction represents the synthesis of lead 

 chloride in the dry way from the elements. The reaction 

 cannot give reliable results for many reasons. The determ- 

 inations made must necessarily be without value. 



Marignac is the only chemist who has used this process. 

 In 1846 he made 3 determinations. The range was moderate, 

 35 ; but the mean is 109 low. This would require Pb = 207.6 

 at least, as the change pero.i is 17 low. 



This is not only absolutely inconsistent with the determ- 

 inations of Berzelius, but conflicts also with the u demands " 

 of the sulphate and nitrate, which would require an atomic 

 weight considerably below 207. 



The only thing to be done is to throw out and disregard 

 faulty processes. 



Our chemical record of atomic weight determinations 

 should cease to be a stinking olla podrida, filled by the use of 

 bad analytical methods. 



The ninth reaction represents the change of nitrate, 

 effected by heating it carefully with an excess of sulphuric 

 acid. 



This is a very questionable operation for atomic weight 

 determination. Only Turner, in 1833, tried it three times. 

 The range was small, 12; the mean was 66 high. 



By our table we see that this would require the atomic 

 weight of lead to be taken at 204.8. 



It is preposterous to consider such a result seriously. 



The tenth reaction is the unreliable silver process in the 

 wet way. 



Marignac, in 1858, made 4 determinations with a range of 

 101 the mean was 18 high. Dumas, in 1860, gave a mean 47 

 high. 



These results would again raise the atomic weight, 

 Marignac about to 207.1, Dumas to 207.3. 



A blunderbuss is a rather poor thing to use where a good 

 rifle is required. 



The eleventh reaction is much worse, since it involves the 

 use of silver chloride in the wet way. 



