THE COMPOSITION OF KULAITE 6 1 I 



especially needful chemically, since, as was pointed out to me 

 by Professor Iddings, judging from the description published in 

 1894, there seemed to be no mineral present which would 

 account for the high alkalis. In addition, for such basic rocks, 

 Al 2 O s seemed to be very high and MgO very low, and it was 

 feared that Dr. Rohrig had made the common error of precipita- 

 ting some MgO along with the A1 3 3 . I am happy to be able 

 to say that two analyses, made by me with especial care in 

 regard to this point, show conclusively that in this respect 

 Rohrig's analyses are quite correct. 



As the rocks have been already described, it is not necessary 

 to go into any lengthy account of their mineralogical features, 

 and only the two analyzed will be mentioned. 



The rock from a depth of 35 meters in a well digging in 

 Kula is light gray, fine grained and slightly vesicular, with small 

 phenocrysts of olivine and pyroxene visible. In thin section 

 phenocrysts of pale gray pyroxene (diopside), olivine and of 

 hornblende, which last in every case have been completely 

 altered to a mixture of diopside and magnetite, are seen lying in 

 a holocrystalline groundmass. This is composed of bytownite 

 laths, small crystals and anhedra of diopside, magnetite grains 

 and small apatites, with an ill defined, colorless mesostasis of 

 low refractive index and small birefringence, which was pre- 

 viously referred to accessory orthoclase. 



The tests made in Leipzig failed to reveal the presence of 

 nepheline, but these have been lately repeated with care, and 

 they prove beyond question that part of this interstitial, anis- 

 tropic substance gelatinizes with acid and stains with fuchsine, 

 while part of it remains unaffected. It is therefore established 

 that nepheline is present in this rock, a conclusion in accordance 

 with the results of analysis, as will be seen later. 



A second specimen to be described is of a " leucite-kulaite," 

 from the northeast flow of Kula Devit, 1 near the Gediz-chai, 



x This was spelled " devlit " in the former papers, following earlier authorities 

 (Hamilton, Tschihatcheff) and as the word was apparently understood by the natives. 

 It is really ciO >t > "devit" an ink-stand, and not ci>J*t> "devlit" state or govern- 

 ment. Cf. Inaug. Diss., p. 12. 



