And if it were asked how it is known that the pocket in which Erskine kept this key was sewn on to the front of his underhose, the answer to that would be this, that one day when Erskine was doing his number one against a bush, Watt, who as Lachesis would have it was doing his number one too against the same bush, but on the other side, caught a glimpse, through the bush, for it was a deciduous bush, of the key, gleaming among the flap buttons.
Source: wiktionary