Section 198 in The Indian Contract Act, 1872

Title: Knowledge requisite for valid ratification.

Description: No valid ratification can be made by a person whose knowledge of the facts of the case is materially defective.

Title: Effect of ratifying unauthorized act forming part of a transaction.

Description: A person ratifying any unauthorized act done on his behalf ratifies the whole of the transaction of which such act formed a part.

Title: Ratification of unauthorized act cannot injure third person.

Description: An act done by one person on behalf of another, without such other persons authority, which, if done with authority, would have the effect of subjecting a third person to damages, or of terminating any right or interest of a third person, cannot, by ratification, be made to have such effect. Illustrations (a) A, not being authorized thereto by B, demands, on behalf of B, the delivery of a chattel, the property of B, from C, who is in possession of it. This demand cannot be ratified by B, so as to make C liable for damages for his refusal to deliver. (b) A holds a lease from B, terminable on three months' notice. C, an unauthorized person, gives notice of termination to A. The notice cannot be ratified by B, so as to be binding on A.

Title: Termination of agency.

Description: An agency is terminated by the principal revoking his authority; or by the agent renouncing the business of the agency; or by the business of the agency being completed; or by either the principal or agent dying or becoming of unsound mind; or by the principal being adjudicated an insolvent under the provisions of any Act for the time being in force for the relief of insolvent debtors.

Title: Termination of agency, where agent has an interest in subject-matter.

Description: Where the agent has himself an interest in the property which forms the subject-matter of the agency, the agency cannot, in the absence of an express contract, be terminated to the prejudice of such interest. Illustrations (a) A gives authority to B to sell A's land, and to pay himself, out of the proceeds, the debts due to him from A. A cannot revoke this authority, nor can it be terminated by his insanity or death. (b) A consigns 1,000 bales of cotton to B, who has made advances to him on such cotton, and desires B to sell the cotton, and to repay himself out of the price, the amount of his own advances. A cannot revoke this authority, nor is it terminated by his insanity or death