1367 
TABLE I. 
fain iii } Cr ‚radiation Cr ,-radiation 
mm. and [103 sin? ~|——— —— 
estimated 2 4E ee 
intensity Eh? oles 2| hyhghg | Xh’ tale 2, hyhohg 
calculated ‚calculated 
1 2 3 4 5 6 i] 8 
NM 170 oi a i 110 
47 5 zs 214 2 213 110 
10.4 m 428 4 427 200 
81.0 zz 535 6 530 211 
91.6 s _ 640 6 640 211 
116.1 ms 852 8 854 220 
1202 zz 879 10 884 310 
: : 2% k ear 
the estimated intensities; tm column 2 the values for 10°sin?— calculated 
: 2 
from this (on account of the slight absorption in the lithium correction 
for the thickness of the rod was here unnecessary). In the well- 
known way the values referring to p-lines have been separated by 
the aid of the ratio 4g: Aa = 2,079 . 10-8: 2,284 .10-8. In corres- 
pondence with the regular crystalline form a common factor for 
vi 
10° sin? = of the a-lines was found, great 218,4. In connection with 
density, atomic weight, value of AvoGapro and wave-length (resp. 
0,534, 6,94, 0,6062.10** and 2,284.10-8) it follows that if the 
number of particles per cell is n, a value for the common factor 
A is calculated for n = 2, which corresponds with the observation 
and is equal to half the factor mentioned, while for A = 106,7 
follows n=1,99; hence per cell (lattice parameter a=3.50 . 10- Sem.) 
there are two particles. In connection with the intensities of the 
diffraction lines, those of planes with odd > / being absent, it is 
obvious that lithium crystallizes in centered cubes’). 
Table Il gives the observed and calculated intensities, in which 
only the factor of the number of planes, the factor of Lorentz, and 
the structure factor (which in this case is the same for the planes with 
1) Hurr already studied lithium, but could not decide between cubes with 
two atoms per lattice-point and centered cubes. Phys. Rev. 10, 661 (1917). 
