The parliamentary enemies of that remarkable sailor and reformist Thomas Cochrane, 10th earl of Dundonald, referred to him disparagingly as a Sawney, which from context I knew to mean a Scotsman. What’s wrong with that, I thought, he was Scottish after all. So I looked the word up and found that although it is an alteration of Sandy, short for Alexander, in British use it also meant fool or simpleton. A neat insult.

From a review of a book about him:

Popularly known as "The Sea Wolf" for his daring, skill, and enterprise, Thomas Cochrane, Earl of Dundonald, was one of the finest frigate captains to fight in Nelson's navy. Christopher Lloyd's vivid biography paints a memorable portrait of the leader, inventor, and reformer whose courageous actions inspired the works of Frederick Marryat, C. S. Forester, and Patrick O'Brian.

I wonder how many perpetrators of the insult would have
cared to do it to his face?

Well, a good point. But although Cochrane was involved in at least one duel that I have read about so far, he was horrified to have killed his man and swore he would never be so tetchy again. He did have a quick temper (a red-headed Scot, what would you expect).

The reviewer was, I think, wrong in describing him as an inventor. It was his father the 9th Earl that was the inventor. Good at inventing but bad at business. When Cochrane joined up as a Middy, his father had to borrow money to pay for the uniform.

And we have our own Sawney, I mean Sonny, here in the States...