Aqua Fortis is the historical name used in alchemy during the Middle Ages. Its literal translation means 'strong water' and it was used to dissolve silver and most other metals. In ancient times, Aqua Fortis was made from a mixture of Saltpeter and sand, Alum or Vitriol, then distilling it by a hot fire. As the gas cooled, it condensed and it was produced. Aqua Fortis was a 'Corrosive' solution of the acid whose chemical formula is HNO3.
The acid had many uses in bygone days. It was used by diamond cutters to separate diamonds from metalline powders. It was also used in decorative crafts for staining such materials as bone, ivory or wood. Mosaic craftspeople used Aqua Fortis to colour the wooden pieces, whilst it was also used to etch brass or copper plates.
Today, the acid is one of the mostly widely used mineral acids, highly 'Corrosive' and 'Toxic'. When pure, it is a colourless solution whilst older samples of material tend to acquire a 'yellow' hue. This is due to the oxides of Nitrogen which accumulate in the material. the acid is classed as 'Fuming' when its concentration is stronger than 86%; this material is also known as Fuming Aqua Fortis and Fuming HNO3.
The acid has many uses in industry, particularly in the production of fertilizers. Aqua Fortis is also used to produce explosives such as TNT (tri-Nitro Toluene) and Nitroglycerine. TNT is produced in a three-step nitration process, full details of which can be found on the Uses pages of this website, together with further information about the uses of Aqua Fortis in the fertilizer industry.
Aqua Fortis has a number of important uses in the laboratory including cleaning and etching glassware and dissolving metals for laboratory analysis. Aqua Fortis is still used today to purify and extract gold and in chemical synthesis. Further details of these and other laboratory uses can be found under ' in the Laboratory.'
Corrosive and Toxic qualities
Due to its highly Corrosive and Toxic qualities, it is essential that the potential hazards and safety implications of Aqua Fortis are clearly understood before handling or working with the material. Full Personal Protective Equipment (PPE) including approved safety glasses or goggles, protective clothing, nitrile gloves and approved safety shoes or boots should always be worn. Aqua Fortis should be handled within the confines of a fume cupboard, particularly in the case of concentrated solutions or Fuming HNO3 or Fuming Aqua Fortis as the fumes released can be particularly damaging soft tissue.