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graphite enveloping each grain acts as a protection against the 
absorption of moisture. 
Graphite, on account of its extreme softness and unctuous 
ness, is admirably suited for use as a lubricant. It is used in 
two manners; namely, dry, or mixed with oil or grease. In the 
accompanying tables, showing the consumption of minerals, 
graphite used in the manufacturing of these mixed lubricants 
is included, but only in a few cases record is made of the graphite 
used in the dry form as a lubricant. Flake graphite in various 
grades of fineness, from about 20 mesh to 200 mesh, is that 
employed and should be free from gritty matter. 
Large quantities of graphite are used in the manufacturing 
of paints for special purposes, such as for covering structural 
steel work, iron and steel tanks, and steel stacks. It produces 
a good weather and fume resisting paint. For this purpose a 
very fine, air-floated flake graphite is used. It should be free 
from grit and sulphide minerals. 
In the casting of iron, it is desirable to coat the inner surface 
of the mould with some material which will prevent the metal 
from coming into contact with the sand of which the mould is 
made, and at the same time give to the casting a smooth surface. 
Graphite possesses certain properties which suit it to this purpose, 
and large quantities are used by the foundry men. A fine grain, 
flake graphite is used, either alone or mixed with talc or ‘sea- 
coal.’ 
Lead pencils are made by encasing thin rods of prepared 
graphite in wood to give the necessary strength. These rods 
are formed by mixing very finely ground amorphous graphite 
with clay, which is then moulded into shape and baked. The 
hardness of the finished product depends upon the proportion 
of clay used and the temperature and duration of baking. 
In electrical work graphite finds many uses on account 
of its conductivity, refractoriness, and softness. For different 
uses various grades are employed, in all of which a high degree 
of purity is required, especially for the making of dynamo and 
motor brushes, in which case it must contain no grit. 
Graphite is used by electrotypers for giving an electro- 
conductive surface to the matrix on which the electrotype is