Before writing the letter it would be important to choose the point in the story where Dr. Jekyll is writing to Mr. Hyde.
Jekyll's feelings about Hyde change over the course of the story, so his letter to Hyde would sound different if he was writing at the very beginning of the "experiment" or if he was writing the letter towards the end of the story when he has lost control of Hyde.
- Dr. Jekyll wants to know what Hyde is doing (you could ask this at any point in the story)
- Dr. Jekyll wants to encourage Hyde
- Dr. Jekyll wants to discourage Hyde
- Dr. Jekyll wants to provide for Hyde and let him know how
- Dr. Jekyll wants to confide in Hyde about how HE is feeling (like one friend to another)
- Dr. Jekyll wants to warn Hyde
- Dr. Jekyll wants Hyde to apologize