In physics, the term Pouillet effect refers to an exothermic reaction that takes place when a liquid is added to a powder. It was first observed by Leslie in 1802 when dry sawdust was wetted with water. Claude Pouillet later described this phenomenon in 1822 when it came to be known as the Pouillet effect in France.
- Leslie, John (1802). "On capillary action". Philosophical Magazine. 1st series. 14: 193–205. From p. 201: Upon wetting paper or linen with water or oil, and " … applying a delicate thermometer, I perceived a very sensible extrication of heat invariably to take place during such combinations. And this effect was the greater in proportion to the previous dryness of the solid. Thus I have sometimes produced a heat of ten degrees by moistening saw-dust which had been parched before the fire."
- Pouillet (1822). "Mémoire sur de nouveaux phénomènes de production de chaleur" [Memoir on new phenomena of heat production]. Annales de Chemie et de Physique. 2nd series (in French). 20: 141–162. From p. 142: "À l'instant où un liquide mouille un solide, il y a dégagement de chaleur." (At the instant when a liquid wets a solid, there is a release of heat.)
- 'Adsorption by powders & porous solids: principles, methodology and applications' Academic Press, 1999.