One of the most practical laboratory tools ever created was the bunsen burner. It was named after the German chemist Robert Wilhelm Bunsen in the 19th century. This is quite unusual as he did not actually invent it but only contributed to its development, it was in fact the work of his technician C. Desaga. The bunsen burner is designed to give off an extremely hot though non-luminous flame, which excludes any traces of soot deposits on the subjects being heated.
The burner is comprised of a narrow metal tube. Gas is injected under a certain amount of pressure through a small jet close to the bottom of the tube. As the gas enters the tube, air is collected in through holes which are level with the jet. The mixture can then be ignited from the top. Proportionally, the air is usually 3 parts to 1 part of gas. With this ratio the compound will burn with a blue flame. If the volume of air is lessened (this is done by rotating a metal band which partly covers the airholes) the burner will produce a luminous and smoky flame that is orange/yellow in colour. With the previous ratio (3 to 1 gas mixture) the flame will consist of two separate zones. The first is the internal midpoint flame, which consists of partly burnt gas. This partial lighting is usually an amalgamation of hydrogen, carbon dioxide, carbon monoxide and nitrogen, although this is dependent on the type of gas being used. In the external oxidizing zone (the second zone) the gases are completely burned. This is due to the oxygen present in the surrounding air, this is always the hottest area of the flame.
