150 ART. 3. — B. kot5; 



become useless for microscopic and chemical studies, as most of 

 the sublimates are deliquescent, and intermixed with intricate 

 aggi'egates. 



(a) The main mass of the above incrustation is composed of 

 salmiac.the salmiac, NHiCl, in the form of rhombic dodecahedrons, 



PBINCIPAIj 



Sublimate gometimcs flattened on the face (110).'^ The dodecahe- 

 drons were picked out, dissolved in water to remove solid im- 

 purities, and then evaporated to a white mass. This was analysed 

 by Mr. Y. Yoshimatsu and Assist. Professor Y. Shibata of our 

 University, giving 9 9. 6 OX of NH^Ol, besides a slight trace of Fe. 

 The writer dissolved the same dodecahedrons in water and allowed 

 the solution to evaporate on an object glass. Under the microscope 

 the preparation proved to be skeletal crystals of salmiac, besides 

 a number of characteristic rhomboid tablets of gypsum crystals. 

 The gypsum is a never-failing compound in volcanic exhalation. 



(b) The yellow or orange -colored aggregate may be hexagonal 

 molysite. Feds', or rhombic erythrosiderite, IKGl-FeCk'HiO. 



(c) The ruby-red tip-aggregate may possibly be octahedral 

 kremersite, KGl-NE^Gl-FeCk + Sz 0. 



Y. Shibata made qualitative tests on a specimen sent to the 

 wi'iter from Kagoshima. A mass of sublimates, found as incrusta- 

 tions on a slaggy lava, is a white crystalline aggregate of gypsum, 

 as can be readily recognized under the microscope, with a yellow 

 coating. The other compounds were found to be the following : 



i. The solution extracted in water contains a small quantity 

 of NHiCl, besides SOi and a trace of CI. 



ii. Treated with hot aqua regia, the solution shows the pre- 

 sence of Ga, Mg, Fe (trace) and ICSO^. 



1) M. MisAWA, Jow. Geol. Soc. Tokyo, p. 96, 1916. 



