11.   Police said a substance was found on the dart used in the attack Wednesday night.

12.   Similar delays occurred last Saturday, when a powdery substance was found on soda cans in the galley of a plane flying to Houston from Minneapolis.

13.   Such substances are also found in nonirradiated foods and in foods processed by any method, including canning, freezing and ordinary cooking.

14.   The decision came after three recent incidents in which powdery substances were found on Northwest planes, prompting calls to the authorities to test for anthrax.

15.   The substance is found in products as diverse as yogurt and eyeshadow, say researchers from the University of Michigan Medical Center in Ann Arbor.

16.   Whatever substance it might find in the charges, the ethics committee is unlikely to look into them before election day.

17.   Police said Thursday that no illegal substances were found among medication seized Tuesday by customs officers from the Bigmat team.

18.   Police sources, speaking on condition of anonymity, said Thursday that no illegal substances were found among medication seized Tuesday by customs officers from the Bigmat team.

19.   A ministry spokesman, speaking on customary condition of anonymity, said no dangerous substances were found in tests at the same federal lab.

20.   Also Monday, two post offices in Toronto and one outside Montreal were evacuated when powdery substances were found by workers.