Yamaka is the sixth book of Abhidhamma. This book is in ten chapters, each dealing with a particular topic of Buddhist teaching: Roots (Mula), Aggregates (Khanda), Bases (Ayatana), Elements (Dhatu), Truths (Sacca/Satya), Formations (Sankhara/Sanskara), Latent States (Anusaya), Consciousness (Citta/Chitta), Phenomena (Dhamma) and Sense Faculties (Indriya).
Colophon:
In CS 1283, a ruang rao year, on the fourteenth waxing-moon day of the third [lunar] month, the third day of the week as the Mon say, a kot set day as the Tai say, the third propitious time, ahaṃ nāmakara, I, Novice Paññā, inscribed this manuscript during my stay of assistance to Svādhu Gambhīra at Wat Huai Ha Phi Chai Nam Long Long Li, Hariphunchai district, in the vicinity of Makhlasom. I wish a new rebirth in the period of Metteyya Buddha. [The manuscript] was completed at the time of the morning drum. The principal initiator was Police Sergeant Bunpan, together with his wife and his children, who sponsored the writing of this manuscript entitled Abhidhammā-yamaka, so that Buddhism could be prolonged until [the end of] 5,000 years.
Other notes:
This date corresponds with Tuesday, 13 December 1921 (1283 Margasirsha 14).