(under subclass 438) Subject matter including means whereby the interior of the vessel or material contained therein is indirectly heated from an electrical source of heat energy by means of a heat transmission medium other than air, such as metallic or liquid heat transfer means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
430, for similar subject matter combined with a vessel and stand.
530, for heating devices under the class definition combined with particular housing means including heat storage or transfer means.
540, for significant heating unit structure including heat
