1887.] 



Presents. 



81 



1. The crimson line is due to alumina, but it is capable of being 



suppressed by an accompanying earth which concentrates 

 towards one end of the fractionations. 



2. The crimson line is not due to alumina, but is due to the 



presence of an accompanying earth concentrating towards the 

 other end of the fractionations. 



3. The crimson line belongs to alumina, but its full development 



requires certain precautions to be observed in the time and 

 intensity of ignition, degree of exhaustion, or its absolute 

 freedom from alkaline and other bodies carried down by preci- 

 pitated alumina, and difficult to remove by washing ; experience 

 not having yet shown which of these precautions are essential 

 to the full development of the crimson line and which are 

 unessential. 



4. The earth alumina is a compound molecule, one of its con- 



stituent molecules giving the crimson line. According to this 

 hypothesis alumina would be analogous to yttria. 



It is not unlikely that a chemist wishing to obtain alumina of 

 exceptional purity might submit it to a series of operations, akin to 

 fractionation, which would have the effect of giving earths phos- 

 phorescing either with a strong crimson line, or with little or no 

 crimson line ; and either of these samples of alumina might be looked 

 upon by 'him as pure. It is possible that some such explanation as 

 this may be at the bottom of the contradictory statements respecting 

 the crimson line of alumina. 



Presents, January 13, 1887. 



Transactions. 



Baltimore : — Johns Hopkins University. Studies. Historical and 

 Political Science. 4th Series. XI-XII. 8vo. Baltimore 1886. 



The University. 



Batavia : — Bataviaasch Genootschap van Kunsten en Wetenschap- 

 pen. Tijdschrift. Deel XXXI. Aflev. 4. 8vo. Batavia 1886 ; 

 Notulen. Deel XXIY. Aflev. 3. 8vo. Batavia 1886 ; Catalogus 

 der Numismatische Verzameling. Derde Druk. 8vo. Batavia 

 1886. The Society. 



Natuurkundige Vereeniging in Nederlandsch Indie. Natuur- 

 kundig Tijdschrift. Deel XLY. 8vo. Batavia 1886. 



The Association. 



Brighton : — Brighton and Sussex Natural History Society. Annual 

 Report. 8vo. Brighton 1886. The Society. 



Brisbane : — Geographical Society of Australasia. Queensland 

 Branch. Report of Second Ordinary Meeting. 8vo. Brisbane 

 1886. The Society. 



