Mosquito coil

A mosquito coil is a mosquito-repelling incense, usually made into a spiral, and typically made using dried paste of pyrethrum powder. The coil is usually held at the center of the spiral, suspending it in the air, or wedged by two pieces of fireproof netting to allow continuous smoldering. Burning usually begins at the outer end of the spiral and progresses slowly toward the center of the spiral, producing a mosquito-repellent smoke. A typical mosquito coil measures around 15 centimetres (6 in) in diameter and lasts around seven to twelve hours. Mosquito coils are widely used in Asia, Africa, South America, Canada, Mexico and Australia.

Invention

Pyrethrum is an insecticide naturally obtained from the drying of plants of the genus Tanacetum and has been used for centuries as a repellent in Persia and Europe.

In the early 19th century, the Austrian Johann Zacherl discovered that the population of the Caucasus used the dried flowers of Chrysanthemum to repel insects. After founding an import-export company in Tbilisi in 1842, he returned to Vienna in 1854 where he soon after opened a factory to produce a "deadly tincture for insects" called Zacherlin, which was sold worldwide.

In 1862, Giovanni Battista Zampironi founded a pharmaceutical laboratory in Mestre for the production of "piroconofobo" ("a fumigating cone that scares away [mosquitoes]"), later renamed fidibus insettifugo (a fidibus was a paper spill used in the 19th century to light pipes and cigars). Zampironi's trapezoidal cones (35 mm long and weighing 2.5 grams) were made with a formula composed of 50% pyrethrum powder, 35% potassium nitrate for combustion, and 15% binders and thickeners (including marshmallow root and tragacanth gum).