Changing the date in a note only one day, without the surety's consent,was held to be a material alteration, even though the change was made to express the real intention of the parties. This case is an illustration of showing the strictness of the courts in forbidding any tampering with a written contract. In that case the law held it to be a material alteration and sufficient to discharge the surety,21 and it may be said to be the policy of the law to discourage anything that would tend to interfere with the maintenance of the integrity of written instruments. The law does not distinguish between an alteration of a written instrument made by the creditor or by the principal debtor; the surety will be discharged by any alteration unless the change in the instrument is by spoliation; that is, an alteration done, which is the act of a third person, or the result of accident.22

19 Patterson vs. McNeeley, 16 Ohio State 348; Hessell vs. Johnson, 63 Michigan, 623.

20 Kirkpatrick vs. Houk,80 I11., 122. 21 Newman et al vs. King, 54 Ohio State, 273.

A change in the duties of the principal will release the surety who has given a bond for the due performance of the duties of the principal's office.23 So any alteration in the contract which increases the responsibilities of the principal debtor will discharge the surety on the original contract.

An extension of time given by the creditor to the principal, without the surety's knowledge and consent, is a frequent ground for claiming a discharge, both because of the alteration of the contract and because the risk of the surety is thereby increased.24 But the law requires the extension agreement to be founded on a proper consideration, in order that it work a release.25 And the granting of additional time could not be held to discharge the surety where the surety has been fully indemnified against loss by the principal's putting him in possession of property sufficient to pay the debt.26 The holder of a guaranteed note does not discharge the guarantor by taking collateral security of the maker without extending the time. Taking additional security does not weaken the original contract, nor take from the grantor any advantage.27 It could only be a benefit.

22 Murray vs. Graham, 29 Iowa, 250. 23 National Mechanics Banking Asso. vs. Conkling, 90 N. Y 116. 24 Bowmaker vs. Moore, 7 Price, 223.

25 Robinson vs. Dale, 38 Wis., 330. 26 Chilton vs. Robbins, 4 Ala., 223. 27 Sigourney vs. Wetherell, 6 Metc, 553.