194 HINRICHS— ATOMIC WEIGHT OF VANADIUM. [April 2:. 



vanadic acid used by Berzelius reminds us of the homely but sound 

 scriptural advice habitually given by Berzelius to his disciples : " do 

 not strain at a gnat while swallowing camels." The phosphoric acid 

 in the vanadic acid used by Berzelius was detected by Roscoe in the 

 sample which Berzelius had presented to Faraday ; but the molybdic 

 reagent necessary for the detection was not known to chemistry in 

 the year 183 1 when Berzelius did his work on vanadium. 



As a matter of fact, Berzelius did not see this gnat; but his 

 work shows that he did avoid some of the camels that stalk about 

 the laboratories and which were deglutinated unconsciously forty 

 and eighty years after Berzelius failed to strain that gnat. The 

 error-shares due to the oxygen are the fattest and most numerous 

 of these camels, up to the present day. 



Our Method of Reduction. 



In order to solve the riddle of the conflicting experimental data 

 obtained in the chemical laboratories of the world during an entire 

 century of painstaking work, we have, especially in the last quarter 

 century, carried on special researches on the proper mathematical 

 reduction of this kind of laboratory work. 



The final results of this extended research are briefly sum- 

 marized in five tables of wdiich two only have thus far been pub- 

 lished. Our work itself has been published in the following books 

 and special papers : 



" The True Atomic Weights," St. Louis, 1894, xvi -\- 256 pp., 

 8vo, with 7 plates and many illustrations. Dedicated to Berthelot. 



"The Absolute Atomic Weights." St. Louis, 1901, xvi -|- 304 pp., 

 8vo, with portrait of Berzelius and three plates, 



" The Proximate Constituents of the Chemical Elements," St. 

 Louis, 1904, with 7 portraits, many plates, 112 pp. text, 8vo. This 

 is an inductive treatise of the subject. 



The " Cinquantenaire," 1910, gives some historical data, copies 

 of older papers, letters in fac-simile and " Fragments inedits " with 

 fine diagrams ; 66 pp., 4to, with plates and portraits. 



" Notes " published in the Coinptcs Rcndiis of the Academy of 

 Sciences of Paris from 1873 to the present, almost sixty in number. 



