nency, the following is a good formula: 1 part bismuth chloride,
2 parts mercury bi-chloride, 1 part copper chloride, 6 parts
hydrochloric acid, 5 parts alcohol, and 50 parts lamp-black, these
being all well mixed. To use this preparation successfully--the
article to be blacked or bronzed being first made clean and free from
grease--it is applied with a swab or brush, or, better still, the
object may be dipped into it; the liquid is allowed to dry on the
metal, and the latter is then placed in boiling water, the temperature
being maintained for half an hour. If, after this, the colour is not
so dark as is desired, the operation has simply to be repeated, and
the result will be found satisfactory. After obtaining the desired
degree of colour, the latter is fixed, as well as much improved
generally, by placing for a few minutes in a bath of boiling oil, or
by coating the surface with oil, and heating the object till the oil
is completely driven off The intense black obtained by this method is
admirable.

Another black coating for ironwork, which is really a lacquer, is
obtained by melting ozokerite, which becomes a brown resinous mass,
with a melting-point at 140 deg. F. The melted mass is then further heated
to 212 deg. F., the boiling-point of water. The objects to be lacquered
are scoured clean by rubbing with dry sand, and are dipped in the
melted mass. They are then allowed to drip, and the ozokerite is
ignited by the objects being held over a fire. After the ozokerite has
burned away, the flame is extinguished, and the iron acquires a firmly
adhering black coating, which resists atmospheric influences, as well
as acids and alkalies. If the black iron vessels are to contain
alkaline liquids, the above operation is repeated.

A good cheap stock black paint or varnish for ironwork is prepared, as
follows: Clear (solid) wood tar, 10 lb.; lamp black or mineral black,
1-1/4 lb.; oil of turpentine, 5-1/2 quarts. The tar is first heated in
a large iron pot to boiling-point, or nearly so, and the heat is
continued for about 4 hours. The pot is then removed from the fire out
of doors, and while still warm, and not hot, the turpentine, mixed
with the black, is stirred in. If the varnish is too thick to dry
quickly, add more turpentine. Benzine can be used instead of
turpentine, but the results are not so good. Asphaltum is preferable
to the cheap tar.

To make another good black varnish for ironwork, take 8 lb. of
asphaltu