(o) Gordon v. Buchanan, 5 Yerg. 81.

(p) Combe's Case, 9 Rep. 75 b, 76 a; Harralson v. Stein, 50 Ala. 347; Drum v. Harrison, 83 Ala. 384; Lynn v. Burgoyne, 13 B. Mon. 400; Connor v. Parker, 114 Mass. 331; Wright v. Boynton, 37 N. H. 9; McCormick v. Bush, 38 Tex. 314.- This maxim has frequent application in cases of powers. Ingram v. Ingram, 2 Atk. 88; Alexander v. Alexander, 2 Ves. Sen. 643; Hamilton v. Royse, 2 Sch. & L. 330. A notice to quit given by an agent of an agent, is not sufficient without a recognition by the principal. Doe v. Robinson, 3 Bing. N. C. 677. - And see Clark v. Dignum, 3 M. & W. 319; Ess v. Truscott, 2 M. & W. 385. - A broker cannot delegate his authority. Henderson v. Barnewall, 1 Y. & J. 387; Cockran v. Irlam, 2 M. & Sel. 301, n. bound by obligations cast upon him by one he does know, and because he knows him would refuse to employ. But, on the other hand, the principal may, if he chooses, give this very power to his agent. (q) In the common printed forms of letters of attorney, we usually find the phrase, " with power of substitution," and after this a promise to ratify whatever the attorney, "or his substitute," may lawfully do in the premises. That the agent has this power, when it is given to him in this way, cannot be doubted. But it must be as certain that the principal may confer the same power otherwise; and not only by other * language, but without any express words whatever. (r) And there are many acts which an agent must necessarily do through the agency of other persons, and which are valid when so done. (s) If a principal constitutes an agent to do a business which obviously and from its very nature cannot be done by the agent otherwise than through a substitute, or if there exists in relation to that business a known and established usage of substitution, in either case the principal would be held to have expected and have authorized such substitution. (t)1 So too, where an agent without authority appoints a substitute, the principal may, either by words or acts, so confirm and ratify such substitution, as to give to it the same force and effect as if it had been originally authorized. (u)

Nor can a factor. Solly v. Rathbone, 2 M. & Sel. 298; Catlin v. Bell, 4 Camp. 183. - A distinction, however, is to be taken between the employment of a servant and the delegation of the authority. An agent, like another person, may act by the hand of a servant as well as by his own hand, in cases where the act is merely physical, or where mind enters into it so little that it would be absurd to say that the difference between one mind and another could be of any moment. Lord Ellenborouqh, Mason v. Joseph, 1 Smith, 406. See also Powell v. Tuttle, 3 Comst. 396; Moor v. Wilson, 6 Foster (N. H), 332; Comm. Bank of Penn. v. Union Bank of N. Y.. 1 Kern. 203; Williams v. Woods. 16 Md. 220; Grady v. American Ins. Co. 60 Mo. 116; Newell v. Smith, 49 Vt. 255.

A substitute of an agent who had no authority to appoint him, cannot be held as the agent of the original principal, but is only the agent of the agent who employs him, (v) and who is accordingly his principal; and the person so employed is bound only to his immediate employer, and can look only to him for compensation. (w)1 But a substitute appointed by an agent who has this power of substitution, becomes the agent of the original principal, and may bind him by his acts, and is responsible to him as his agent, and may look to him for compensation.

(q) Palliser v. Ord, Bunb. 166. - A power coupled with an interest, given to A and Ms assigns, passes with the interest to A's devisee, to the executor of that devisee, and to the assignee of the devisee, etc, for the word assigns includes both assignees in law and in fact. How v. Whitefield, 1 Vent. 338, 339; s. c. as How v. Whitebanck, 1 Freem. 476.

(r) Moon v. Guardians of Whitney Union, 3 Bing. N. C. 814; Gillis v. Bailey, 1 Foster (N. H.), 149.

(s) Rossiter v. Trafalgar Life A. A., 27 Beav. 377.

(t) An architect employed by defendants to draw a specification for a building proposed to be erected, himself employed the plaintiff to make out the quantities, which work was to be paid for by the successful competitor for the building contract; the jury found a usage for architects to have their quantities made out by surveyors; it was held that the plaintiff was entitled to recover compensation from the defendants. Moon v. Guardians of Whitney Union, 3 Bing. N. C. 814; Ledoux v. Goza, 4 La. An. 160.

(u) Tindal, C. J., Doe v. Robinson, 3 Bing. N. C. 677, 679; Mason v. Joseph, 1 Smith, 406.

(v) Cobb v. Becke, 6 Q. B. 930; Rob-bins v. Fennell, 11 id. 248.

1 An insurance agent may authorize his clerk to do various acts, as sign and issue policies and receive premiums. Bodine v. Exchange Ins. Co. 51 N. Y. 117; Grady v. Am. Cent. Ins. Co. 60 Mo. 116. An agent may direct his clerk to sign a document Norwich Univ. v. Denny, 47 Vt. 13. A collection agent may employ a notary to present and protest a note. Tiernan v. Commercial Bank, 8 Miss. 648. And see Ken-wick v. Bancroft, 56 Ia. 527.

An agent is bound to great diligence and care for his principal; not the utmost possible, but all that a reasonable man under similar circumstances would take of his own affairs. (x) And where the instructions are not specific, or do not cover the whole case, there, as we have already stated, he is to conform to established usage, as that which was expected from him. (y) This usage may be generally proved by ordinary means; but in some instances, as in relation to negotiable bills and notes, it is required and defined by the law; and here it must be followed precisely. (z) And an agent is bound to possess and exert the skill and knowledge necessary for the proper performance of the duties which he undertakes. (a)

(w) Corbett v. Schumacker, 83 Ill. 403; Cleaves v. Stockwell, 33 Me. 341. And see Butler v. Michigan Central R. R. Co. 60 Mich. 83.