652 



exactly = 2, but somewhat smaller. The values of V-^Ak calculated 

 from (2) will, therefore, be sooner too large than too small, when we 

 shall take for the present =z J in what follows. 



5. Calculation of the values of i .4/, from Q,. 



Let us begin with hy I rogen. hsxRDY [l^io) deievimned Q^ := dbOOO 

 G-r. cal., whereas Langmuir (well-known method) gave 132000 Gr. cal. 

 in 19J2. But the latter found from 70000 to 80000 Gr. cal. in 1914. 



We are therefore not very far from the truth, when for H, 

 we put the value of Q, at round 90000 Gr.cal. With 7\. = 33,18 

 (K. Onnes, Crommki.in, Oath, 1917) Q„ : II- becomes therefore = 2700, 

 hence '/,.Q,: 71- = 402. And as \ ai = l,l (see table II), we get 

 (all the values of \Ui'i, and \/ Ak are still to be multiplied by IQ-''*) : 



[/Ak = 1,1 X 1/403 = 2.08 = 22, 

 which is in very good harmony with what we have found for Li (23) 

 and Na(27) (see table II). 



For nitrogen Brinkr ') calculates Q^=-.M least 150000 Gr. cal. 

 from a single value given by Langmuir. This value of Briner's seems 

 too high to me considering the values for H, and for (),, and in my 

 opinion 130000 Gr. cal. will be nearer the truth. When we calculate 

 \Ak from the two values of Q^, we get * ^. Q^ : 2\=z\I^.:k 



/-.. 



/150000 \ /1190\ ,^^. ,_^ V J X - u • 



: 12(5 = \' . X L.o« = 176 to lo3. And V a\ being = 

 ^180000 ) '" \\02>2j 



= 2,6, we get: 



\/Ak = 2,6 X l/^^' = 34,6 or 32,3 =35 or 32. 



As in connection with C = 32 also a value in the neighbourhood 

 of 32 can be expected for N, the result is also here a confirmation 

 of our formula (1) or (L?)' the more so when we bear in mind 

 that the result may possibly be slightly too high in consequence of 

 our having put <9 = 1 . • 



For Oxygen Siegel '■') has found Q^ = 1 60000 Gr.cal. Hence 

 7,7^^0 ■■ Tk here becomes = V',7 X (160000 : 154.25) = 7,7 X 1040 = 

 = 154. With rrt';fc = 2,6 we find further: 



y/Ak = 2,6 X 1/155 = 32,4 = 32, 



which is again in excellent agreement. 



In the second place we shall examine the Halogens. 



First of all Chlorine. Pier =') found the value 113000 Gr.cal. for 



1) Journal de Chem. Phys. 12, 119 (1914) and 13, 219 and 465 (1915). 



2) Zeitschr. f. physik. Chem. 87, 642 (1914). Gf. also Briner, I.e. 



3) Ibid. 62, 385 (1908). 



