A brief review is given of the electrical properties of liquid metals and alloys with special reference to alkali metal based alloys and the liquid alkaline earths. Attention is then focussed on structural problems associated with liquid alloys particularly those in which a gradual transition occurs from metallic to semiconducting behaviour as the composition is varied. Experimental evidence will be presented against structural models which involve the notion of clusters. An explicit connection between the structural properties on the one hand and the electronic properties on the other will be suggested