Frederick Boyle, Chinese Secret Societies (1891)
“ Both Penang and Singapore had beheld troubles almost as grave. Perak was a native state at the time, rich in antimony mines, which had attracted fifty thousand Chinamen, every single one belonging to a society established at Penang. Freed from all restraint, they followed their own instincts. The Malay Rajah did not interfere so long as they paid their dues. Pitched battles were incessant. On one occasion thirty thousand men engaged, of whom two thousand were left dead upon the field. The mother lodges at Penang took up these quarrels and attacked one another. ”
