“By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths.”
King James Version (KJV)
Re 9:18 By these three. "By these three plagues" (Revised Version). The fire, smoke and brimstone. These agencies slay the third part of men. We have before found that the Old Roman world was divided into three parts. One third part had been destroyed by the first four trumpet invasions. A second third part was taken by the Saracens. If now the third part was taken and destroyed by these three plagues, the symbolism would be fulfilled.