What is the butter incident in the packing lesson of beehive

In the story 'packing for the journey' by Jerome k Jerome, when Harris and George starting packing the food hampers, George got butter stuck on his slippers as he trod over it. They got the butter off the slipper when they came to know about it. As they put the butter on the chair, Harris when sits on the chair get it stuck on his back. Therefore, they again start searching all over for the butter. At last, they find the butter behind Harris. In this story, the incident of butter creates a lot of humor.