Bread and Butter Pickles

1 gallon thinly sliced pickles
2 cups sliced onions
1/2 cup salt
4 cups sugar
1 tsp turmeric
4 Tbsp white mustard seed
1 tsp celery seed
about 1 1/2 qts cider vinegar

Slice cucumbers and onions into very thin slices.
Put into plastic bowl
Mix with salt and sugar
Let stand for at least 3 hours then drain nearly dry
Put cucumbers and onions into saucepan.
Mix rest of ingredients together and pour over cucumbers and onions
Place over very low heat and cook until simmering - DO NOT allow to boil
Place in hot sterilized jars and seal