434 A. P. COLEMAN 
and calcite. If we subtract the lime and carbonic acid, as form- 
ing calcite, and the ferric oxide with a proportionate amount of 
water (.45 per cent.), as forming limonite, we have left the 
following: 
Al,O3 - - - - 10.90 pO Sir 
Na,O - - = - 6.60 .106 =1 
H,O (at red heat) = a) Alghi) IDNA — (2426 
Reducing to molecular ratios, alumina and soda are equal, 
and water stands at 2%, proportions that correspond to those of 
analcite, except for a little too much water. 
If the alumina in analcite equals 10.90 per cent. the corre- 
sponding amount of silica, four molecules, is 25.49 per cent., 
and the whole percentage of analcite in the rock is almost 
exactly 47, nearly one half. In the second part treated 
with acid, when 30.35 per cent. proved soluble, the amount of 
analcite must be more than half the whole weight of rock taken 
If we subtract the percentages of substances found in the first 
portion of rock dissolved in hydrochloric acid from the results of 
the complete analysis, and also the proper amount of silica to 
form analcite with the alumina, soda, and combined water, we 
shall have left the materials forming the insoluble ingredients of 
the rock. j 
The complete analysis given below was made by Mr. H. W. 
Charlton, his results being put in column I. In column II an 
analysis by Dr. Mann of cancrinite-aegyrite-syenite from Siksj6- 
Berg in Dalarne’ is given because of its rather close resemblance 
to No. 1; and in column III an analysis of analcite-basalt from 
the Basin, Colorado, by W. F. Hillebrand.? 
A little more than 46 per cent. of the rock remains unac- 
counted for by the partial analysis ; and if we suppose the whole 
of the potash to belong to orthoclase and the unused portion of 
iron oxide (1.40 per cent.) to belong to aegyrite, we have left 
* Neues Jahrbuch fiir Mineralogie, 1884, II, p. 193; as quoted by ZIRKEL, Lehr- 
buch der Petrographie, Band II, p. 410. 
2 WHITMAN Cross, an Analcite-Basalt from Colorado, Jour. GEOL., Vol. V, No. 
7, 1897, p. 689. 
