List at least three rhetorical devices that Patrick Henry used in his “Speech in the Virginia Convention.”

Patrick Henry makes use of several allusions—indirect references to an event, text, person, etc.—in order to borrow the weight and emotional tenor of the original. He asks the president,

"[...] I wish to know what there has been in the conduct of the British ministry for the last ten years, to justify those hopes with which gentlemen have been pleased to solace themselves and the House? Is it that insidious smile with which our petition has been lately received? Trust it not, sir; it will prove a snare to your feet. Suffer not yourselves to be betrayed with a kiss."

Henry refers to the disciple, Judas, who, in the Bible, betrayed Jesus Christ for thirty pieces of silver. He identified Jesus for his persecutors by kissing Jesus on the cheek; thus, we say "betrayed with a kiss" to describe a great and terrible act of betrayal. In using this allusion, Henry raises to a Biblical level that betrayal perpetrated by the English government of the colonists.
Henry also uses logos, appeals to the audience's logic, in order to convince them of his position. He says,

"For my part, whatever anguish of spirit it may cost, I am willing to know the whole truth—to know the worst and to provide for it. I have but one lamp by which my feet are guided; and that is the lamp of experience. I know of no way of judging of the future but by the past."

This is quite a logical position, that the best indicator of future behavior is past behavior. Therefore, if the British monarchy has been deceptive in the past, one's experience with it ought to prepare one for a similar deceptiveness in the future.
Henry also uses rhetorical questions, questions for which no answer is expected because it should be clear within the minds of hearers, to great effect. These questions are phrased in such a way that the audience will be inclined to answer in the way Henry would wish. For example, he asks,

"Has Great Britain any enemy, in this quarter of the world, to call for all this accumulation of navies and armies? No, sir, she has none. They are meant for us; they can be meant for no other. They are sent over to bind and rivet upon us those chains which the British ministry have been so long forging. And what have we to oppose to them? Shall we try argument? Sir, we have been trying that for the last ten years. Have we anything new to offer on the subject? Nothing."

This is quite effective because Henry knows that his audience will have to answer these questions for themselves in a particular way, and so they even begin to convince themselves of the truthfulness of his arguments as they listen.