Pe ete 
ae CS Oe ee Lt oe ee et a eS eee 
: 
F. D, Adams—Chlorine in Scapolites. 317 
and the sulphuric acid precipitated in the filtrate by barium 
chloride. Since as before mentioned alkaline chlorides are lost 
I. an 
SiO, 54°859 54-858 54-859 
Al,O; 22°128 22-769 22°448 
Fe,0; 86 486 
ad 9°164 9-020 9°092 
MgO trace. trace. ce 
K,0 1°241 1-013 1127 
Na,O0 8°358 8373 8-365 
Cl (2°473) 2-485 2°276 2% 2-411 
SO; “823 0 “796 
H.O (comb.) "143 “139 141 
H.O (hygr.) 122 123 722 
100-409 100°427 100°447 
Deduction for O replaced by Cl, *59 59 
99°819 99°837 99-857 
Assuming chlorine and sulphuric acid to be combined with 
sodium, the atomic and quantivalent ratios calculated from the 
mean of the above analyses, are: 
Atomic. Quantivalent. 
si 914 x 4 3656 3656 
438x3 1314 
Fe 006 x3 18 ' ae 
- 162 x2 324 324 $ 1886 
a 206 206 
K 024 24 t _ 
NaCl 8 
Excluding NaCl and Na,SO,, the quantivalent ratio for 
basic elements and silicon is 1886: 8656=1: 1-94, approxi- 
mately that required by a bisilicate (1:2). It is therefore more 
acidic than any of the members of the scapolite family with 
the exception of dipyre and marialite. 
As many of the analyses given in Dana’s Mineralogy foot up 
to less than 100, some of them being as low as 97 and 98, it 
