298 Professor Anderson on the 



amorphous mass : but if it be distilled to a small bulk, and 

 left for a day or two in a cool place, as already mentioned, it 

 becomes filled with granular crystals. These are collected on 

 a filter, and pressed between folds of filtering paper, to remove 

 the resinous mother liquor. The pressed mass is re-dissolved 

 in boiling ether, and the crystals deposited, on cooling, are 

 again expressed, and this is repeated until it is obtained en- 

 tirely free from resinous matters. It then forms a mass of 

 yellow crystals, having a fine satiny lustre, which is seen to 

 great advantage when a fluid containing it in suspension is 

 stirred. Under the microscope these crystals are seen to be 

 minute plates, which are much broken up, and show no well- 

 marked form. Rottlerine is insoluble in water, sparingly so- 

 luble in cold alcohol, more so in boiling. In ether it is readily 

 soluble. It dissolves in alkaline solutions, with a dark-red 

 colour. Its alcoholic solution is not precipitated by acetate of 

 lead. Bromine instantly decolorizes it, with formation of a 

 substitution product, which dissolves readily in spirit, and is 

 thrown down by the addition of water. It does not crystallize, 

 and could not be obtained in a state of purity. Nitric acid oxid- 

 izes Rottlerine, forming at first a yellow resinous matter, and 

 by longer continued action, a quantity of oxalic acid. Concen- 

 trated sulphuric acid, in the cold, dissolves it with a yellow 

 colour, which, on the application of a gentle heat, first becomes 

 red, and finally very dark, sulphurous acid being evolved. 

 Heated on the platinum knife, it fuses into a yellow fluid, 

 which decomposes at a higher temperature, giving off pungent 

 fumes, and leaving a bulky charcoal. 



The specimens employed for analysis were from different 

 preparations, and the results were : — 



{4*332 grains of Rottlerine gave 

 11-026 ... carbonic acid, and 

 2-235 ... water. 



( 4-295 grains of Rottlerine gave 

 II. < 10*885 ... carbonic acid, and 

 ^2175 ... water. 



( 4*150 grains of Rottlerine gave 

 III. < 10-505 ... carbonic acid, and 

 2-096 ... water. 



