Cairncross Vs Lorimer [3 Macq. 827]

Lord Chancellor, "The doctrine will apply, which is to be found, I believe, in the laws of all civilized nations that if a man either by words or by conduct has intimated that he consents to an act which has been done, and that he will offer no opposition to it, although it could not have been lawfully done without his consent, and he thereby induces others to do that from which they otherwise might have abstained, he cannot question the legality of the act he had so sanctioned, to the prejudice of those who have so given faith to his words or to the fair inference to be drawn from his conduct. I am of opinion that, generally speaking, if a party having an interest to prevent an act being done has full notice of its being done, and acquiesces in it, so as to induce a reasonable belief that he consents to it, and the position of others is altered by their giving credit to his sincerity, he has no more right to challenge the act to their prejudice than he would have had if it had been done by his previous license."