There are in later times other decrees, made by popes of another
kidney.
Barrow.
Millions in the world of this man's kidney.
L'Estrange.
Your poets, spendthrifts, and other fools of that kidney, pretend,
forsooth, to crack their jokes on prudence.
Burns.
This use of the word perhaps arose from the fact that the kidneys and
the fat about them are an easy test of the condition of an animal as to
fatness. "Think of that, -- a man of my kidney; -- . . . as subject to
heat as butter." Shak.