Atomic 





number. 



Element. 



Z. 





13 



Al 



14 



Si 



15 



P 



16 



S 



the Absorption of X-Rays. 179 



Substance j n nL IV 

 examined. 



Mehd 4-08 3-66 3'23 2'79 



C 6 H 5 Si(CH 3 ) 3 5-68 505 4-39 3-70 



H 3 P0 4 6-16 5-47 4-82 4-18 



HoS0 4 7-99 6-81 6-04 5-21 



Na" 2 S 2 3 7-99 7"30 6"12 4-83 



Meau 7-99 7'06 60S 5'02 



17 01 HC1 1025 894 765 639 



NaCl 10-01 8-94 7"53 714 



Mean 1013 8'94 7-59 676 



19 K KCJ 14-7 12-6 11-6 92 



K S 15-1 13-3 11-5 9-7 



Mean I4'9 12-9 11*5 9'4 



20. Ca CaCl, 21-3 18'9 15'6 1P2 



Ca(K0 3 ) 2 19-8 18 15'4 129 



Mean 20'5 18'4 155 12"0 



23 V !S T a 4 V. 2 O r 34 ' 8 30 ' G 27 ' 2 22 ' 5 



24 Cr K 2 O0 4 40" 1 35-7 30-5 25*3 



K Cr.,0 39-6 '<56» 30-1 25"6 



CrCL" 39-7 366 31-9 24'8 



Mean 39-8 36-3 30-8 252 



Mn MnCl 462 40'9 356 28-9 



MnS0 4 48-6 42-0 36'4 28'8 



Mean 47*4 41-4 36'0 28-9 



26 Fe Metal 55*1 48'7 40-8 33-3 



FeCl 3 51-5 44-3 39*7 32-1 



Fe(]N T 'H 4 ),(S0 4 ) 2 ... 57-2 48-1 41 '4 33'5 



- Mean 54'6 470 40"6 33'0 



Co CoOl, 67-6 57'0 51"8 40'6 



Co(N0 3 ) 2 64-0 55-5 47'2 36-9 



Mean 65"8 56*2 49"5 38*8 



28 Ni Metal 69"7 63-8 54*5 46-8 



NiCl 2 70-1 63-0 550 43'2 



Mean 69-9 634 547 45*0 



29 Cu Metal 8P0 66*9 54-8 47*4 



CuCl 2 78-0 69-5 59-1 485 



CuS0 4 78-4 70-0 61-0 49'4 



Cu(N0 3 ) 2 78-4 64-8 55-5 48*3 



Mean 78*9 67'8 57'6 48-4 



