Yes, dry mustard can safely be used as a substitute for mustard seed. However, it may make the brine cloudier than mustard seed and may alter the flavor.   1 teaspoon mustard seeds = 1Â½ teaspoons dry mustard.
Humeston is a city in Wayne County, Iowa, United States. The population was 494 in the 2010 census, a decline from 542 in the 2000 census.
The town is in the Greater Hume Shire Council area which was established in May 2004 from the merger of Culcairn Shire with the majority of Holbrook Shire and part of the Hume Shire. At the 2011 census, Holbrook had a population of 1,263 people.