Apply

With 'apply' command you can use certain substances, such as salves and pastes, on other objects or beings. The syntax is : 
        'apply <substance> to <target>'. 
For example 'apply salve to sword' would spread your poison salve all over your sword's blade. If there is no visible effect, it is very probable that the substance cannot be applied to the target you specified, i.e. healing salve would not help much when applied to an arrowhead. Also note that the target is searched first from your inventory and after that from your surroundings.