Mix together sugar, mustard, salt, and vinegar.
Let stand 3 hours, stirring about every 30 minutes, until of a honey consistency.
Heat one-half of the oil; to it add paprika.
Strain and cool.
Add paprika oil to remainder of salad oil and beat it slowly into first mixture.
Last, add celery seed and let stand 24 hours at room temperature.
(If dressing separates, beat well before using.)