Very scarce work by Irish divine, James Gray [1770-1824]. He emigrated to the United States and became pastor of the Associate Reformed church in Philadelphia. This work available in this and one other edition; both scarce. 

Gray, James. A Dissertation on the Priesthoods of Jesus Christ and Melchisedec, in Three Parts; Together with the Life of Christ, Ministry of John the Baptist, Review of Southey's Wesley, Christian Unity, Holy Spirit on the Heart, etc. New York. Robert Carter & Brothers. 1852. 172pp

Good - copy; very sound and ready for use, but rubbed and with a significant tide mark across lower third of binding and text block.