Treason
2 of the 7 encyclopedias on this shelf carry an entry for Treason. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
HIGH, that crime which is directly committed against the supreme authority of the State, considered to be the greatest crime that can be committed. Formerly in England certain offenses against private superiors were ranked as petit or petty treason, and it was in opposition to such offenses that treason against the sovereign was called high treason; but by an act of George IV. high treason was made the only England comprehends the following descriptions, namely: (1) Compassing or imagining the king's death. (2) Violation of the king's companion (meaning the queen), his eldest daughter, unmarried, or the wife of the eldest son and heir. (3) Levying war against the king in his realm. (4) Adhering to his enemies in his realm, and giving them aid and comfort in the realm or elsewhere. (5) Counterfeiting the great or privy seal. (6) Slaying the chancellor, treasurer, etc. The third of the offenses detailed in this statute is now treason felony and has a milder punishment than treason annexed to it. Clause 5 is now repealed. The English law condemns the person convicted of treason to be drawn hurdle to the place of execution, there to be hanged, and then beheaded and quartered; and a conviction was followed by forfeiture of land and goods and attainder of blood; but this is now restricted to hanging, forfeiture and attainder being abolished. The concealment of treason is called misprision of treason. In the United States treason consists in levying war by a citizen against the country, or adhering to its enemies. In the session of Congress (1901-1902) several measures were introduced making any attack on the life of the President, govern- Vice-President, or certain other ment officials an act of treason, and punishable by death. The provision was also introduced that the offender should be tried by the Federal Courts, thus removing such cares from the jurisdiction of State courts at the place of the occurrence.
Aiton's Encyclopedia (1910)
tre'zn, an offense against the government. To prevent ambiguity, the Constitution of the United States contains a provision as follows: "Treason against the United States shall consist only in levying war against them or in adhering to their enemies, giving them aid and comfort. No person shall be convicted of treason unless on the testimony of two witnesses to the same overt act, or on confession in open court." No one has been punished seriously for treason in the United States. April 30, 1790, an act was passed, making treason punishable by death. Aaron Burr was tried under this act, but was permitted to take his departure. At the close of the Civil War Jefferson Davis was confined on charge of treason, but was dismissed finally. In 1844 Rhode Island convicted Dorr of treason, but public sentiment did not permit the sentence to be carried into effect. In England, however, a charge of treason was for centuries a common way of getting rid of a political opponent. The list of illustrious persons confined in the Tower and executed for treason is a long one. The punishment approved by custom and law was for a long time disemboweling while alive, beheading, and quartering. The present penalty is hanging. See Tower; Burr ; Rhode Island ; Russia