Electrically conductive synthetic fiber and fibrous substrate (e.g. synthetic leather) are disclosed. The electrically conductive polymeric fiber and polymeric fibrous substrate are made electrically conductive by the use of an electrically conductive polymer disposed on the fibers and in contact with inorganic desiccant particles located at the surface of the fibers. The new material finds utility as an electrode for devices and as a resistive heating element, and as a pathway to efficient thermoelectrics.

Provided is an optical fiber glass preform in which a starting rod and a dummy glass are hardly separated from each other, and a method for manufacturing the glass preform. In the optical fiber glass preform, the dummy glass is fitted into one end of the starting rod, and a part of the dummy glass and the starting rod are surrounded by a clad glass. In the manufacturing method, at the time of connecting the starting rod and the dummy glass, a shape is adjusted in such a manner that an iron is brought into contact with a connection portion and is moved from a starting rod side toward a dummy glass side with appliance of a load.