by any subsequent independent act of the party, or of another, with which it has no connection, regardless of whether the first act was done for a good or a bad purpose.*

The prohibition may be either by the common or unwritten law," or by statute. But it must be by one or the other. And an executive officer or department of the federal government cannot, by its rules. or regulations, make that a crime which has not been made a crime by Congress."

of the blow and the date of the death. People v. Gill, 6 Cal. 637.

4 A statute providing that every person respecting whom voluntary or involuntary proceedings in bankruptcy are commenced who within three months before their commencement obtains goods upon credit by false pretenses shall be punished, comes within this rule, and is unenforceable. United States v. Fox, 95 U. S. 670, 24 L. Ed. 538.

A senator elect who, before he is sworn in or assumes the duties of his office, receives a bribe to proeure an appointment for another cannot be convicted under a statute making it an offense for a member of congress to accept a bribe for such a purpose, though he afterwards is sworn in and takes his seat. United States v. Dietrich, 126 Fed. 676.

infra.

5 See § 19 et seq.,
6 See § 24 et seq., infra.

7 United States v. Eaton, 144 U. S. 677, 36 L. Ed. 591, 12 Sup. Ct. 764; St. Louis Merchants' Bridge Terminal Ry. Co. v. United States, 188 Fed. 191; Patterson v. United States, 181 Fed. 970; Robnett v. United States, 169 Fed. 778; United States v. Keitel, 157 Fed. 396, rev'd on other grounds 211 U. S. 370, 53 L. Ed. 230, 29 Sup. Ct. 123; United States v. Bedgood, 49 Fed. 54; United States v. Manion, 44 Fed. 800.

"Regulations prescribed by the President and by the heads of depart

ments, under authority granted by
congress, may be regulations pre-
scribed by law, so as lawfully to
support acts done under them and in
accordance with them, and may thus
have, in a proper sense, the force of
law; but it does not follow that a
thing required by them is a thing so
required by law as to make the neg-
lect to do the thing a criminal offense
in a citizen, where a statute does not
distinctly make the neglect in ques-
tion a criminal offense. United
States v. Eaton, 144 U. S. 677, 36
L. Ed. 591, 12 Sup. Ct. 764. Quoted
in United States v. Keitel, 157 Fed.
396,
rev'd on other grounds 211
U. S. 370, 53 L. Ed. 230, 29 Sup. Ct.
123; United States v. Maid, 116 Fed.
650.

A wholesale dealer in oleomargarine failing to keep a book showing his sales or to make monthly reports showing his receipts and sales, as required by regulations made by the commissioner of internal revenue, cannot be prosecuted under a provision of the act for the punishment of any dealer in oleomargarine who fails or omits to do "any of the things required by law in the carrying on or conducting of his business,' although the state also authorizes the making of such regulation. United States v. Eaton, 144 U. S. 677, 36 L. Ed. 591, 12 Sup. Ct. 764.

The secretary of agriculture cannot add by regulations to the class of railroad companies and the acts

§ 18. Estoppel. In some jurisdictions it is held that the state, in a criminal prosecution, may not invoke the doctrine of estoppel against the accused to establish a material element of the offense. So it has been held that a person charged with having sexual intercourse with a female of previous chaste character is not estopped to show that she was unchaste when the offense was alleged to have been committed because he had previously had intercourse with her in another state; that the fact that a person charged with seduction denies all intercourse does not estop him from claiming that the state has adduced evidence from which the jury may find that the element of previous chastity has not been established beyond a reasonable doubt; 10 and that the fact that a person who is charged with assault and battery, and who sets up self-defense, insists that he repelled something more than a simple assault and battery does not estop him from objecting to a charge making his right of self-defense depend upon the fact that he was in danger of death or great bodily harm.11 And it has also been held that the doing of acts forbidden by a statute which applies only to persons of a certain class does not estop the defendant from denying that he belongs to that class. 12 Other courts, however, hold that the doctrine of estoppel may be applied in criminal as well as in civil cases.18 And the rule, applicable in civil actions, that one who

punishable under the Stock Quarantine Act of March 3, 1905, St. Louis Merchants' Bridge Terminal Ry. Co. v. United States, 188 Fed. 191; or extend the provisions of the Act of May 29, 1884, relating to the transportation of diseased animals out of quarantined districts SO as to include animals not diseased. United States v. Hoover, 133 Fed. 950.

A charge of perjury cannot be based upon words added to a statutory oath by a rule or regulation of an executive department, nor upon an oath required by such a rule or regulation, but not required by statute. See § 864, infra.

But congress and state legislatives may delegate to officers, tribunals or boards power to determine a fact or state of things upon which the action of a law depends, or to make and enforce administrative regulations

for the execution of a statute according to its terms and make the violation of such regulations a crime. See § 34, infra.

8 Bailey v. State, 57 Neb. 706, 78 N. W. 284, 73 Am. St. Rep. 540, and other cases cited in the following notes.

9 Bailey v. State, 57 Neb. 706, 78 N. W. 284, 73 Am. St. Rep. 540. 10 State v. Cameron, 177 Iowa 379, 158 N. W. 563.

11 State v. Stansberry, 182 Iowa 908, 166 N. W. 359.

12 Moore v. State, 53 Neb. 831, 74 N. W. 319.

13 People v. Treadwell, 69 Cal. 226, 10 Pac. 502; State v. Spaulding, 24 Kan. 1; State v. District Court of Second Judicial Dist., 31 Mont. 428, 78 Pac. 769, 3 Ann. Cas. 841; Price v. State, 10 Okla. Cr. 427, 137 Pac. 736; Ellington v. State, 7 Okla. Cr.

receives money or any other thing of value in the assumed exercise of authority as agent for another is estopped to deny such authority, has frequently been invoked criminal prosecutions. 14

II. THE COMMON LAW

§ 19. Definition, nature and sources. By the "common law" is meant that portion of the municipal law which does not rest for its authority upon any express act of the legislature, but is founded upon. usage and custom. It is called the unwritten law, in contradistinction to the written or statute law.15 Its principles are to be determined

from treatises, reports, and the like,16 and it is sufficient if a particular case can be brought within those principles, although no exact precedent for it can be found.17 The common law of crimes, as recognized and enforced in this country, consists of the common law of England as it existed at the time of the independence of the United States, as supplemented and modified up to that time by such British statutes as were of a general nature and not local to that kingdom,18 in so far, and only in so far, as its principles are applicable

to the conditions of the country and the necessities of the people, and are not repugnant to the laws or the established customs and usages of the people of the various states, 19 together with some usages adopted by general consent by the American colonists prior to the revolution.20

§ 20. Recognition and adoption in the United States. The common law is generally in force in the various states of this country,21 to the extent stated in the preceding section,22 except in so far as it has been abolished, superseded, or modified by statute.23 And in