Term invented by van Helmont to denote a mystical spirit or vital force which presided over and governed the various processes of the body. Each bodily function was supposed to have its own special blas; blas appears to be the counterpart of the archaeus (q.v.) of Paracelsus.
[a Middle E. variant of blast]
Search Stedman's Medical Dictionary
Examples: glitazone, GI cocktail, etc.