92 



BUREAU OF AMERICAN ETHNOLOGY 



[bull. 52 



tlie presence of a relatively large amount of socialite together with 

 a large excess of quartz, which is obviously contrary to experience. 

 The tests with silver nitrate cited above indicate that the chlorine 

 is contained in NaCl, which has probably been derived from sea 

 water, and this assumption was made in calculating the analysis 

 in order to obtain the most favorable conditions for proving the 

 eruptive nature of the rock. But even with tins assumption, the 

 analysis does not resemble that of any known lava. 

 Chemical analysis, of Dr. E. Herrero Ducloux. — 



84.73 



9.95 



99.012 



Baiios 



ni Sal 84. 73 7 , 



^^^^^ Fem~ 9.95>1--- ^ 



^, Q 4^3.84 ^5^3 „ 



Order F = 37:22<3>5 ^ 



^ K,0' + Na,0' .0249^3^1 



^^^g CaO- = l)86-<5>7 ^ 



^ ^ K,0' .0052 3 1 



^"^^^^g N^' = .-0197<5>7 -^ 



01. Escoria. Chapadmalal, E. H. "Ducloux, analyst. 

 a. Molecular proportions of 01. 



The calculation of this analysis indicates its close similarity with 

 the first. Both analyses belong to subrangs for which no representa- 

 tive has yet been found in normal lavas. These rocks are abnormal 

 and the conclusion of Dr. H. Bucking and Colonel Romero that the 

 rocks are normal andesites can not be considered justifiable. 



Scoria from San Bias. — Both the microscopic and chemical e\adence 

 prove that this rock 'is a normal andesitic lava. It is unusually 



