red color, which is increased by converting the substance
into the chloride.

THE ACID ELEMENTS

24. ~Borates.~--If the substance be finely powdered, moistened with
glycerine, and then placed on a platinum wire in the Bunsen flame, it
imparts a brilliant green color.

If turmeric paper be dipped into a solution of a borate, and then be
dried at 100 deg. C., it is turned to a peculiar red color. These two
reactions are extremely delicate.

25. ~Bromides.~--Bromides treated with microcosmic salt and oxide of
copper on platinum wire impart to the flame a greenish-blue color, the
edges being decidedly green.

26. ~Chlorides.~--Chlorides are treated in the same way as bromides. The
color imparted to the flame is azure-blue.

To discriminate between bromides and chlorides more clearly, the
substance is mixed with anhydrous potassium bisulphate and fused in an
ignition tube.

Bromine and sulphur dioxide are evolved (if the substance be a bromide),
the tube being filled with a yellow gas possessing the characteristic
odor of bromine.

27. ~Fluorides.~--A small portion of the substance in a finely powdered
condition is placed in one of the ignition tubes, a strip of moist
Brazil-wood paper is introduced into the open end, and heat is applied.
Hydrofluoric acid is evolved, and the red color of the paper is changed
into a straw-yellow.

Mica, containing only 0.75% of fluorine, shows the reaction clearly.

28. ~Iodides.~--Iodides are treated, as the bromides and chlorides, in a
bead of microcosmic salt with oxide of copper. The flame is colored
green.

Fused with potassium bisulphate in an ignition tube the violet vapors of
iodine are evolved, and thus iodides may be distinguished from chlorides
and bromides.

29. ~Nitrates.~--If a nitrate be heated upon charcoal before the Bp.,
violent deflagration occurs. If the substance containing the nitric
acid be mixed with a _very small_ quantity of finely powdered potassium
cyanide, the deflagration is accompanied with ignition and detonation.

If the substance be mixed in a dry condition with dry potassium
bisulphate, and is then heated in an ignition tube, red-brown nitrous
fumes are evolved. This reaction takes place if there is but a small
quantity of nitrate present.

30. ~Phosphates.~--Phosphates impart to the flame a bluish green color.
The color is made more intense by moistening the substance with
sulphuric acid, and then taking the paste so forme