Surat-surat di dalam Jilid 4 ini adalah sebanyak 52 pucuk surat dan bertarikh dari tahun 1786 sehingga 1794. Francis Light banyak berhubungan melalui surat dengan Sultan Selangor dan kerabat-kerabat serta pembesar-pembesar negeri tersebut di dalam jilid ini. Selain perdagangan, Francis Light juga sering menghulurkan bantuan dalam berbagai-bagai cara kepada mereka seperti memberi bantuan pencarian perhiasan, permaidani, senjata dan membantu urusan perniagaan Raja Muda Selangor / Volume 4 consists of 52 letters dated from 1786 to 1794. Francis Light had numerous correspondence through letters with the Sultan of Selangor, Selangor royalties as well as state chiefs in this volume. Other than trade, Francis Light also often provided them with various assistance such as in looking for ornaments, carpets, firearms and in Raja Muda of Selangor’s business matters.
