1817.
Oct^r 1 -
green precipitate which appears to be a sub-sulphate of [ Chrome ]
the solution [filter] is of a fine green it contains both Sulphuric acid & [ Chrome ]
apparently combined as a sulphate of the metal
The chloride of chromium does not diliquesce (no change in 4 days)
Oct^r. 2 -
The green oxide of chromium is not [acted] on by the [sul].
nitric or Muriatic acid but when fused with caustic alkalis it is
converted into chromic acid producing a chromate
When muriate of chromium is evaporated to dryness & [heated]
to about redness in close tubes the chloride usually is not entirely soluble in
water but a portion remains which when washed & dried is of a dull
dark green colour this appears to be a sub chloride of chromium
This sub chloride when treated with alkali is converted into
an oxide & chlorine may be found in the solution by nit of silver if the heat
be [can] high the oxide becomes acidifed & then remains in solution but this
causes no ambiguity in the test because of the colour of chromate of silver.
After being heated for a long time in close vessels [it still] with [treating]
by alkali gave abundance of chlorine - but when heated in the open air
chlorine flies off & an oxide remains of a black colour but apparently the
same with the green oxide in this [trial] with alkali is converted into chromic
acid but no traces of chlorine remain in the solution
Oxide of Chrome when just precipitate dissolves in small
quanitites in Ammonia giving it a pink colour by evaporation to
remain behind unaltered
Oct 3
Oxide of Chrome newly precipitated dissolves in Mur acid the
dried and heated oxide does not
Muriate of chromium is precipitated by chromate of Ammonia