Grate or finely chop 1/2 large head cabbage and 1 small onion together. Place in a large bowl.
Boil together 1/3 c vinegar, 1/3 c vegetable oil, 1/2 c sugar, 1/2 tsp salt. Be sure that the chopped cabbage and onion are well mixed. Pour the boiling hot dressing over the vegetable mixture. Now, don't touch it. Just leave it as it is for 1 1/2 hours, before mixing or tossing together.
Now mix and store in a covered container at least 12 hours before serving.
Jen made this with purple cabbage, and I made it with white cabbage, and it's delicious. Works well with 1/3 c sugar instead of 1/2. From Cooking Down East by Marjorie Standish.