Computer graphics space-filling representation of a molecule of nitroglycerin, an explosive. A molecule loaded with either nitro- (NO2) or nitrate (NO3) groups becomes highly explosive. Nitroglycerin has 3 nitrate groups (the nitrogen atom is blue, oxygen red) and was first made in 1845 by the action of nitric acid on glycerin. Nitroglycerin is easily detonated & consequently dangerous to prepare. It came into use after 1867, when the Swedish chemist Alfred Nobel combined it with a diatomaceous earth called Kieselguhr to make dynamite in 1867. Dynamite retained the explosive power of nitroglycerin yet was relatively safe to manufacture and handle.