208 HINRICHS— ATO^IIC WEIGHT OF VANADIUM. [April 21, 



\\ The Final Departures. 



In this table ( I\'. ) we have finally given all the departures for 

 all the elements taking part in the different reactions used for the 

 determination of the atomic weight of vanadium during the last 

 eighty years — from Berzelius in Stockholm to Edgar F. Smith in 

 Philadelphia. We have fully explained the manner of calculating 

 these departures; every reader can verify any of these values for 

 himself by the methods stated. Since the element most concerned 

 is vanadium, we have arranged the record of departures in the order 

 of the magnitude of the departures of vanadium, for which the ex- 

 treme values are 1062 and minus 307, giving a total range of 1369, 

 say one and one third units of atomic weight ; that is, from Va 52.06 

 to 50.69. 



If we omit the pioneer and preliminary work done by Berzelius 

 in trying reactions (a) and (b), the extreme departures will be 800 

 and — 31. a total range of 831 only. The atomic weights will run 

 from 51.80 to 50.69, which is a remarkably fine showing for so long 

 a series of very difficult w^ork on the rare element. 



To realize the generally excellent work of the early days of Ber- 

 zelius and of Roscoe — when the element was decidedly rare and diffi- 

 cult to purify — we need only compare the limits of the determina- 

 tions by Prandtl of today with the range of the entire series (ex- 

 cluding only, as we have done already, the reactions (a) and (b)) ; 

 these extremes of Prandtl are 594 with reaction 98 and 13 in Series 

 II. with reaction 270; a total range of 581 thousandths. The corre- 

 sponding atomic weights of vanadium are 51.59 and 51.01 differing 

 58 hundredths. 



We are greatly tempted to point out a number of interesting fea- 

 tures on this table, but fear that the paper will assume undue length 

 and trust the reader will help himself. 



We only remind the reader that the letter in the first column of 

 this table permits the ready identification of the experimental result 

 expressed in numbers in this table with the graphical representation 

 on our two diagrams. 



