"Kelso Tracts" were tracts written by Horatius Bonar (1808-1889). This paperback of 42 pages is rich in teachings on the slain Lamb. In the pages are 12 writings that are as follows:
Words of Warning; Two Bible texts are taken to show how the unconverted state of a sinner should cause him to tremble. Isa. 3:11, and 2 Pet. 2:17. It shows your misery and how dark your path is without God.
Electing Love; it shows how He has afore prepared you as a vessel of mercy. Rom. 9:23. How you as the clay were taken by the potter to be formed into a vessel of mercy by God's degree.
Luther's Conversion; using psalm 18:16, and Isa. 54:17 he describes Luther's awakening and unspeakably troubled state, how he wrestled with himself; until he was brought to faith. Finally, one verse stood out to Luther and made his conversion complete, "The just shall live by faith."
Sin Our Enemy and God Our Friend; "Know, therefore, and see that its an evil thing and bitter that thou hast forsaken the Lord thy God" (Jer. 2:19). Is God your friend?
The anchor of the Soul; taken from Heb. 6:19, speaking of the hope we have which is an anchor, sure and steadfast, and with it we can enter into the veil.
Do You Go to the Prayer Meeting?;  using three Bible verses Mal. 3:16, Acts 1:14, and Heb. 10:25 Bonar exhortation for you here is to not forsake the assembling yourself together, but with one accord lift up prayer and supplication and the Lord hears you cries.
Behold He Cometh with Clouds; about Christs return with ten thousand of his saints. (Jude 14) & (Rev. 16:15). Believers are waiting and watching for the Lord's return. 
Who Shall Dwell with the Devouring Fire?; The sinners in Zion are afraid, fearfulness hath surprised the hypocrites; who among us shall dwell with the devouring fire, who among us shall dwell with everlasting burnings? (Isa. 33:14). Warnings for all believers to look for false faith.
The True Heart; "Let us draw near with a true heart." (Heb. 10:22). Where to look.
Without God; two verses that address having no hope in the world, therefore unblessed and unmoved. (Eph. 2:12) and (Jer. 2:12, 13). Here he speaks of the emptiness of this world Having broken cisterns that hold no water.
The Last Time; Using 1 John 2:18, and James 5:8, H. Bonar speaks of the antichrist and the coming of the true Lord Most High!
The false Peace and The True; "They have healed the hurt of the daughter of my people slightly, saying Peace, peace; when there is no peace." (Jer. 6:14).