Ammonium nitrate, formed by the action of ammonia on weak nitric acid, is mixed with chalk to form another fertilizer known as "Nitro-Chalk". A concentrated slurry of ammonium nitrate and chalk is sprayed down a 200-ft tower. In the the picture is the interior of the too of this tower.The British Chemical Industry:Britain woe the original home of the chemical industry and today, when its products are essential to almost all industrial production, the British chemical industry stands in a leading position. From iron ore smelting to the manufacture of clothing materials, modern industry cannot function without a vast range of chemical products, And Britain's great industrial ability is no small measure rooted in the strength of the British chemical industry. It products. enter almost every phase of daily life; they are as essential to the farmer as to the doctor or surgeon, VIII. September 4, 1951. (Photo by British Official Photograph).