Celery Salt is a combination of dried and ground celery seeds or in some cases ite relative lovage seeds, and salt. It has also been know that dried and powdered celery stalk has been used instead of the seeds. It is used in beverages such as a Bloody Mary and is known to be one of the secret herbs and spices used in a well known fast food chicken emporium.
Packaged food producers often use celery salt to prevent spoilage as they avoid listing sodium nitrate as an ingredient.