The prosperity of the town is largely due to the export trade in phosphates, esparto grass, oil, almonds, pistachio nuts, sponges, wool, &c. There is in the Gulf of Gabes a rise and fall of 5 ft.
The environs of Creil (Oise) and Chteau-Landon (Seine-et-Marne) are noted for their freestone (pierre de taille), which is also abundant at Euville and Lrouville in Meuse; the production of plaster is particularly important in the environs of Paris, of kaolin of fine quality at Yrieix (1-Jaute-Vienne), of hydraulic lime in Ardche (Le Teil), of lime phosphates in the department of Somme, of marble in the departments of HauteGaronne (St Beat), Hautes-Pyrnes (Campan, Sarrancolin), Isre and Pas-de-Calais, and of cement in Pas-de-Calais (vicinity of Boulogne) and Isre (Grenoble).
Phosphates and chemical manures; calcitim carbide; explosivi powder; dynamite and other explosives.
The ordinary ammonium molybdate, used as a test reagent for phosphates, is a salt of composition (NH4)10M012041; it has been examined physicochemically by J.
Deficiency of nutritive salts, especially nitrates and phosphates; the presence of poisonous salts of iron, copper, &c., or (in the soil about the roots of trees in towns) of coal-gas and so forth.