247 



the"microscope. We found that after heating at 14340 M. V. (element 111) 

 the whole preparation was again crvslalline. although it had the 

 outward apj^earancc of a glassy, lialI-opa(|uo mass; but on heating 

 at 14360 M. V., all had been changed into a real "glass". The 

 moltingtemperature therefore must be fixed at 14350 M. V. As the 

 correction for the used quenching-svstem (vid. the determinations of 

 the meltingpoint of natural spodumene of Madfujascar) was shown 

 to be practically equal to zero, we can conclude from this, that the 

 meltingpoint thus determined is in full agreement with that found 

 by the dynamical method, and can be put at 1401° C. (G Th.). The 

 crystallized product appeared to be identical with the /:?-modification, 

 later to be described, the refractive index was about: ??=: 1.521; 

 the specific gravity at 25° C : (/40 =: 2,411. 



2. In a similar way the preparation, obtained from lithiumaluminato 

 and SiO^ was investigated; analysis gave the following data: 



I II Calculated: 



SiO, 64,807, 04,07% 64,6V„ 



A O3 27,837„ 28,097„ 27,47„ 

 LIJJ 7,37\i, 7,847, 8,07„ 



This preparation therefore e\'idently can also be considered as a very 

 good one; it contains ca. 0,47o L,iiO too little, and ('.a,.0,5"/oAI^(J.^ 

 too much. 



Fig. 4. 



Arlificial (S-spodumene, obtained from JAAIO., 



and S'iOg ; melted and slowly cooled. 



(X Nicols). 



17* 



