steam distillation is an effective way to separate slightly volatile water insolube substance from nonvolatile material high boiling liqiuds mean less volatile ( non volatile) one boiling mixture of water and this( water insoluble liquid and non volatile ) water evaporates completely leaving pure liquid Solution steam distillation is an effective way to separate slightly volatile water insolube substance from nonvolatile material high boiling liqiuds mean less volatile ( non volatile) one boiling mixture of water and this( water insoluble liquid and non volatile ) water evaporates completely leaving pure liquid.