Turin chemist Ascanio Sobrero, by dripping glycerin (or glycerin—easily obtained from animal fat) into a cooled mixture of sulfuric and nitric acid, and pouring the resulting solution into water, discovered (or invented) nitroglycerin. Then (perhaps unthinkable today) he tasted the resulting compound and noted that even without swallowing, even contact with the tongue caused a severe headache with throbbing and severe weakness in the limbs. It was later discovered that this was due to the dilation of blood vessels, and nitroglycerin was prescribed for angina pectoris. Today we know that the effect is actually due to simple nitric oxide (NO), and research in this field also led to the development of the drug Viagra, which also relies on the vasodilatory effect of nitric oxide. Alfred Nobel’s idea in Stockholm in 1833, however, was to use a small amount of gunpowder to cause the explosion of a large quantity of nitroglycerin. But Nobel also had to try to avoid unwanted explosions. To do this, he used a diatomaceous earth based on Kieselguhr (diatomite—a porous rock made from diatom shells) to dilute the nitroglycerin. In 1867, Nobel & Company began shipping and selling dynamite around the world.
