414 Mr. Tennant on two Metals, found in the Powder 
chemists. The properties of this last metal, which they have 
remarked, are those of giving a red colour to the triple salt of 
platina with sal-ammoniac, of not being altered by muriate of 
tin, and of giving, with pure alkali, a dark brown precipitate. 
M. Vauquelin also adds, that it is precipitated by galls, and 
by prussiate of potash ; but I should rather ascribe these preci- 
pitates to some impurity, and probably to iron. 
As it is necessary to give some name to bodies which have 
not been known before, and most convenient to indicate by it 
some characteristic property, I should incline to call this metal 
Indium, from the striking variety of colours which it gives, while 
dissolving in marine acid. 
In order to obtain the compound of this metal with marine 
acid in a pure state, I tried to make it crystallize. 
By slow evaporation of the solution, only an imperfectly 
crystallized mass was produced; but this, being dried on blotting- 
paper, and dissolved in water, afforded, by again evaporating as 
before, distinct octaedral crystals. These crystals, dissolved in 
water, gave a deep red coloured solution, inclining to orange. 
With an infusion of galls, no precipitate was formed, but the 
colour was instantly, and almost intirely, taken away. Muriate 
of tin, carbonate of soda, and prussiate of potash, produced 
nearly the same effect. Pure ammonia precipitates the oxide ; 
but (possibly from adding it in excess) I found it retained a 
part in solution, acquiring a purple colour. The pure fixed 
alkalis also precipitate the greater part of the oxide, but are 
capable of retaining a part in solution, becoming of a yellow 
colour. All the metals which I tried, excepting gold and platina, 
produced a dark or black precipitate from the muriated solu- 
tion, which is at the same time deprived of its colour. The 
