722 REPORT — 1893. 



performed iu a large porcelain 'basm, using plenty of water, gently rocking and 

 rotating the mixture, and allo-wing it to rest at intervals ; the lighter portions are 

 then su'cked up hy means of a pipette, this being continued until nothing but the 

 copper-coloured crystals are left. 



The largest quantity which has been separated in this way is equal to '032 

 per cent. 



Ferro-manganese containing different percentages of manganese and of different 

 makes has been examined, and, with the exception of spiegeleisen containing 11 per 

 per cent, of manganese, they have all been found to contain this remarkable coni- 

 poimd. 



As the quantities available for examination were small, with the exception of 

 determining the specific gravity and the amount of the titanium only qualitative 

 tests have been applied. In different specimens the specific gTavity has been found 

 to vary between 4-1 and 5-1, and the titanium from GO'5 to 79-8 per cent. These 

 latter determinations include a small proportion of iron, which I have always found 

 to be present ; this is also the case with crystals separated from an old blast-furnace 

 ' bear.' After several days' heating with hydrochloric acid there is 1-5 per cent, iron 

 retained, and probably this is the cause of the crystals being slightly but distinctly 

 magnetic. 



Attention is specially directed to the fact that much valuable information with 

 regard to the condition of the foreign elements may be obtained by decomposing' 

 large quantities of the alloys with suitable reagents, and separating the substances 

 of different specific gravity from the residue. In doing this it is pointed out that 

 there is great" danger of decomposing the compounds originally present, and form- 

 ing new ones as a result of the reaction which takes place between the reagent 

 and the various substances present. Such a method as is indicated in this paper 

 is recommended to be used iu conjunction with the examination of etched speci- 

 mens, which of themselves do little beyond revealing changes of structure induced 

 by different modes of manipulation and varying temperatures. The insufiiciency 

 of etched specimens to give us information with regard to the condition of im- 

 purities is evident from the fact that, being opaque, so nearly alike in colour, and 

 in such minute and uniformly distributed particles, they escape observation. 



SATURDAY, SEPTEMBER 16. 

 The Section did not meet. 



MONDAY, SEPTEMBER 18. 

 The following Eeports and Papers were read : — 



1. Interim, Report on the History of Chemistry. 



2. Report on the Wave-length Tables of the Spectra of the Elements. 



See Reports, p. 387. 



3. Interim Report on the Bibliography of Spectroscopy. 



4. Report on the Bibliography of Solution — See Reports, p. 372. 



