Experiments on Allanite. 283 
dropped in with.caution. A copious reddish-brown pre- 
cipitate fell, which being washed, dried, and heated to red- 
ness in a covered crucible, weighed 25°4 grains. It pos- 
sessed all the characters of black oxide of iron. For it was 
attracted by the magnet, completely soluble in muriatic 
acid, and the solution was not precipitated by oxalate of 
ammonia. 
3. The liquid being still of a brown colour, I conceived 
it not to be completely free from iron. On this account, 
an additional quantity of succinate of ammonia was added. 
A new precipitate fell; but instead of the dark reddish- 
brown colour which characterizes succinate of iron, it had 
a beautiful flesh-red colour, which it retained after being 
dried in the open air. When heated to redness in a co- 
vered erncible, it became black, and had some resemblance 
to gunpowder. It weighed 7-2 grains. 
4. This substance attracted my peculiar attention, in 
consequence of its appearance. I found it to possess the 
following characters : 
a. It was tasteless, and not in the least attracted by the 
magnet, except a few atoms, which were easily separated 
from the rest. 
b. It was insoluble in water, and not sensibly acted on 
when boiled in sulpburic, nitric, muriatic, or nitro-muriatic 
acid. . 
c. Before the blow-pipe it melted with borax and mi- 
crocosmic salt, and formed with both a colourless bead. 
With carbonate of soda it formed a dark-red opake bead. 
d. When heated to redness with potash, and digested in 
watcr, snuff-coloured flocks remained undissolved, which 
gradually subsided to the bottom. The liquid being sepa- 
rated, and examined, was found te contain nothing but 
potash. When muriatic acid was poured bp the snuff- 
coloured flocks, a slight effervescence took place, and when 
heat was applicd, the whole dissolved. The solution was 
transparent, and of a yellow colour, with a slight tint of 
green. When evaporated to dryness, to get rid of the ex- 
cess of acid, a beautiful vellow matter gradually separated. 
Water boiled upon this matter disso!ved the whole. The 
taste of the solution was astringent, with a slight metallic 
flavour, by no means unpleasant, and no sweetness was 
- perceptible, 
e. A portion of the black powder being exposed to a red 
heat for an hour, in an open crucible, became reddish- 
brown, and lost somewhat of its weight. In this altered 
state, it was soluble by means of heat, though with difi- 
culty, 
