foreign substance

“Any time you put a foreign substance into anybody you have the potential for an adverse event,” Geisbert reminds.

Why would I turn around and introduce another foreign substance into my body?

How is this possible when each tablet contains almost one grain of foreign substance (chiefly starch)?

The groundwork of the face was hopefulness; but over it now I ay like a foreign substance a film of anxiety and grief.

Milk is adulterated by watering, removing the cream or by adding some foreign substance.

Did you notice any foreign substance—any accumulation of what might afford fuel for a fire?

Saturated Solution—one which contains as much of the foreign substance as it is capable of holding.