This is how to write an angry letter!
For those of you unfamiliar with 18th century writing, I have transcribed the text
You curst, damned, Hell-Fire Dog, if you don’t answer our first Letter, you damned Dog, I will blow up your House, and kill you wheresoever I meet you. As for the Son of a Bitch your Brother, I will cut him in Pieces, and broil him in Beef-Shakes in the Flames of his own House. You Son of a damned Bitch, obey my Commands, or I will serve you as I will your Brother, for making Game of my last Letter. As for the Names I subscribed in the last Letter, they laughed at it as a Jest; but they shall, like a Pack of Hell-Fire Dogs, find their Houses in Flames in earnest. As for the Proclamation (here he used language not fit to be mentioned).