Which stimulant was widely used as an insecticide in the 1920's and 30's?

In the 1920’s and 1930s, nicotine was widely used as an insecticide. Nicotine is a substance mainly used in tobacco and similar products. It is a mild type of stimulant, increasing a person’s heart rate, which effects in increased alertness. The use of nicotine as insecticide declined because it was found not only addictive, but it causes numerous dangerous effects in human body, particularly in the lungs.

answer; /// i believe that the correct answer is( it left behind rich

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).