Wash cucumbers in cool water and pack into a
canning jar big enough to hold them.
Add sugar, salt, dry mustard and alum. Fill jar about 2/3 full with vinegar.
Fill remaining portion of jar to cover cucumbers with water. Put lid on jar.
Agitate lightly every day for about a week to mix spices in with the cucumbers. Then put in a cool dark place for about 3 months while the cucumbers work.
Don't be too impatient to try the pickles.
THEY TASTE HORRIBLE IF THEY HAVEN'T AGED PROPERLY. AT LEAST A MONTH