DELUSION¹, med. jurisp. A diseased state of the mind, in which persons believe things to exist, which exist only, or in the degree they are conceived of only in their own imaginations, with a persuasion² so fixed³ and firm, that neither evidence nor argument can convince them to the contrary.

2. The individual is, of course, insane. For example, should a parent unjustly persist without the least ground in attributing to his daughter a course of vice⁴, and use her with uniform unkindness, there not being the slightest pretence⁵ or color of reason for the supposition, a just inference of insanity⁶, or delusion, would arise in the minds of a jury: because a supposition long entertained and persisted in, after argument to the contrary, and against the natural affections of a parent, suggests that he must labor⁷ under some morbid⁸ mental delusion. 3 Addams' R. 90, 91; Id. 180; Hagg. R. 27 and see Dr. Connolly's Inquiry⁹ into Insanity, 384; Ray, Med. Jur. Prel. Views., &sect¹⁰;20, p. 41, and §22, p. 47; 3 Addams, R. 79; 1 Litt. R. 371 Annales d'Hygiene Publique, tom. 3, p. 370; 8 Watts¹¹, 70; 13 Ves. 89; 1 Pow. Dev. by Jarman, 130, note Shelf. on Lun. 296; 2 Bouv. Inst. n. 2104-10.

DEMAND, contracts. A claim; a legal obligation.

2. Lord Coke says, that demand is a word of art, and of an extent, in its signification, greater than any other word except claim. Litt. sect. 508; Co. Litt. 291; 2 Hill, R. 220; 9 S. & R. 124; 6 Watts and S. 226. Hence a release of all demands is, in general, a release of all covenants¹², real and personal, conditions, whether broken or not, annuities¹³, recognizances, obligations, contracts, and the like. 3 Tho. Co. Litt. 427; 3 Penna, 120; 2 Hill, R. 228.

3. But a release of all demands does not discharge rent before it is due, if it be a rent incident to the reversion; for the rent was not only not due, but the consideration - the future enjoyment¹⁴ of the lands - for which the rent was to be given, was not executed. 1 Sid. 141; 1 Lev. 99 3 Lev. 274; Bac. Ab. Release, I.

DEMAND, practice. A requisition or a request by one individual to another to do a particular thing.

2. Demands are either express or implied. In many cases, an express demand must be made before the commencement of an action, some of whichwil l be considered below; in other cases an implied demand is all that the law requires, and the bringing of an action is a sufficient demand in those cases. 1 Saund. 33, note 2.

3. A demand is frequently necessary to secure to a man all his rights, both in actions arising on contracts and those which are founded on some tort. It is requisite¹⁵ also, when it is intended to bring the party into contempt for not performing an order which has been made a rule of court.

4. - 1. Whether a demand is requisite before the plaintiff can commence an action arising on contract, depends upon express or implied stipulations of the parties. In case of the sale of property, for example, to be paid for on delivery, a demand of it must be made before the commencement of an action for non-delivery, and proved on the trial, unless it can be shown that the seller has incapacitated himself by a resale and delivery of the property to another person, or otherwise. 1 East, R. 204 5 T. R. 409; 10 East, R. 359; 5 B. & Ald. 712 2 Bibb, 280 Hardin, 79; 1 Verm. 25; 5 Cowen, 516. 16 Mass. 453; 6 Mass. 61 4 Mass. 474; 3 Bibb, 85; 3 Wend. 556; 5 Munf. R. 1; 2 Greenl. 308; 9 John. 361; 6 Hill, N. Y. Rep. 297.

5. On the same principles, a request on a general promise to marry is requisite, unless it be dispensed¹⁶ with by the party's marrying another person, which puts it out of his power to fulfil his contract, or that he refuses to marry at any time. 2 Dow. & Ry. 55; 1 Chit. Pr. 57, note (n), and 438, note (e)

6. A demand of rent must always be made before a re-entry for the non-payment of rent. Vide Re-entry.

7. When a note is given and no time of payment is mentioned, it is payable¹⁷ immediately. 8 John. R. 374; 5 Cowen, R. 516 1 Conn. R. 404; 1 Bibb, R. 164; 1 Blackf. R. 233.

8. There are cases where, a demand is not originally necessary, but becomes so by the act of the obligor. On a promissory note no express demand of payment is requisite before bringing an action, but if the debtor¹⁸ tenders the amount due to the creditor¹⁹ on the note, it becomes necessary before bringing. an action, to make a demand of the debtor for payment; and this should be of the very sum tendered. 1 Campb. 181 Id. 474; 1 Stark²⁰. R. 323; 2 E. C. L. R. 409.

9. When a debt or obligation is payable, and no day of payment is fixed, it is payable, on demand. In omnibus obligationibus in quibus dies non ponitur, presenti die debitur. Jac. Introd. 62; 7 T. R. 427 Barn. & Cr. 157. The demand must, however, be made in a reasonable time, for after the lapse²¹ of twenty years, a presumption²² will arise that the note has been paid; but, like some other presumptions²³, it may be rebutted²⁴, by showing the fact that the note remains²⁵ unpaid²⁶. 5 Esp. R. 52 1 D. & R. 16 Byles on Bills, 169.

10. When demand of the payment of a debt, secured by note or other instrument, is made, the party making it should be ready to deliver up such note or instrument, on payment. If it has been lost or destroyed, an indemnity²⁷ should be offered. 2 Taunt²⁸. 61; 3 Taunt. 397; 5 Taunt. 30; 6 Mass. R. 524; 7 Mass. R. 483; 13 Mass. R. 557; 11 Wheat. R. 171; 4 Verm. R. 313; 7 Gill & Johns. 78 3 Whart. R. 116; 12 Pick. R. 132 17 Mass. 449.

11.-2. It is requisite in some cases arising ex delicto, to make a demand of restoration of the right before the commencement of an action.

12. The following are examples 1. When the wife, apprentice²⁹, or servant of one person, has been harbored by another, the proper course is to make a demand of restoration before an action brought, in order to constitute the party a wilful³⁰ wrongdoer, unless the plaintiff can prove an original illegal enticing³¹ away. 2 Lev. 63: Willes, 582; 1 Peake's C. N. P. 55; 5 East, 39; 6 T. R. 652; 4 Moore's R. 12 16 E. C. L. R. 3 5 7.

13. - 2. In cases where the taking of goods is lawful³², but their subsequent detention³³ becomes illegal, it is absolutely necessary, in order to secure sufficient evidence of a conversion³⁴ on the trial, to give a formal notice of the owner's right to the property and possession, and to make a formal demand in writing of thedelivery of such possession to the owner. The refusal to comply with such a demand, unless justified³⁵ by some right which the possessor may have in the thing detained, will in general afford sufficient evidence of a conversion. 2 Saund. 47, note (e); 1 Chit. Pr. 566.

14. - 3. When a nuisance has been erected³⁶ or continued by a man on his own land) it is advisable, particularly in the case of a private nuisance, to give the party notice and request him to remove it, either before an entry is made for the purpose of abating³⁷ it, or an action is commenced against the wrong doer and a demand is always indispensable in cases of a continuance of a nuisance originally created by another person. 2 B. & C. 302; S. C. 9 E. C. L. R. 96 Cro. Jac. 555; 5 Co. 100, 101; 2 Phil. Ev. 8, 18, n. 119; 1 East, 111; 7 Vin. Ab. 506; 1 Ayl. Pand. 497; Bac. Ab. Rent, 1. Vide articles Abatement³⁸ of Nuisance, and if Nuisance. For the allegation of a demand or request in a declaration, see article Licet scoepius requisitus; and Com. Dig. Pleader, C 70 2 Chit. Pl. 84; 1 Saund. 33, note 2; 1 Chit. Pl. 322.

15. - 4. When an order to pay money, or to do any other thing, has been made a rule of court, a demand for the payment of the money, or performance of the thing, must be made before an attachment³⁹ will be issued for a contempt. 2 Dowl. P. C. 338, 448: 1 C. M. & R. 88, 459; 4 Tyr. 369; 2 Scott, 193; 4 Dowl. P. C. 114; 1 Hodges 197; 1 Har. & Woll. 216; 1 Hodges, 157; Id. 337; 4 Dowl. P. C. 86.