Former Defense Secretary Robert Gates didn't hide his contempt for Senate Majority Leader Harry Reid, D-Nev., when asked to answer Reid's claim that he "denigrated" colleagues "to make a buck" with his new memoir.

"It's common practice on the Hill to vote on bills you haven't read, and it's perfectly clear that Sen. Reid has not read the book. He will find that I do denigrate him," Gates cracked back at a Politico event promoting his new book, Duty: Memoirs of a Secretary at War.

Gates also noted that "a substantial part" of proceeds from his book will be donated to wounded warrior and veterans charities.

Reid said that both he and Vice President Joe Biden were disappointed with Gates. "I'm surprised he would in effect denigrate everybody he came in contact with in an effort to make a buck," Reid told the Associated Press earlier Thursday.

Gates described Reid's 2007 comment that the Iraq war was "lost" as "one of the most disgraceful things I'd heard a politician say" during an MSNBC interview Monday.

In the book, he also faults Reid for calling him with parochial concerns. "With all the major issues we had to deal with, my personal contacts with Senate Majority Leader Reid were often in response to his calls about Air Force objections to construction of a windmill farm in Nevada because of the impact on their radars,” the Daily Caller reported Thursday.

“He also once contacted me to urge that Defense invest in research on irritable bowel syndrome."