then , all at once , a thought of the officers face looking at me , his hand about to touch my shoulder , i tightened , had a sensation the back of my head had been jostled , smacked , bent forward from the nonexistent blow and vomited into the basin , horribly , moaning , the first retch liquid and sweet mash of bread , the following three like perverse ribbits , obscene , nothing but air out while at the same time it was like i was gobbling the same air in .