Page:Violin Varnish and How to Make it.djvu/19

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MONG their many and varied properties, oils have the capacity of marking paper in a greasy fashion, different oils doing so in varying degree of persistence. In this manner we are able to distinguish broadly between oils and the kind known as essential oils.

There is another class, which is not much more than a modification of the first—namely, Siccative oils.

The name Siccative is given to a certain class of oils which are produced by other oils coming into contact with air and, by absorbing the oxygen, acquire the property of drying rapidly.

Linseed oil is naturally siccative, but the process of dessication is exceedingly slow, and commercially the property is of not much value.