Sentence:  ‘Please, sir, Richard says one of the horses has got a very bad cold, and he thinks, sir, if you could make it convenient to go the day after to-morrow, instead of to-morrow, he could physic it to-day, so as—' / ‘Confound his impudence!' <WSD>interjected</WSD> the master. 
Meaning of the word marked with <WSD> tags:  To say as an interruption or aside.