section_path: History/Discovery and use/Robert Boyle
section_name: Robert Boyle
paragraph_text: Robert Boyle
  
  In 1671, Irish scientist Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas.
  
  Having provided a saline spirit, which by an uncommon way of preparation was made exceeding sharp and piercing, we put into a vial, capable of containing three or four ounces of water, a convenient quantity of filings of steel, which were not such as are commonly sold in shops to Chymists and Apothecaries, (those being usually not free enough from rust) but such as I had a while before caus'd to be purposely fil'd off from a piece of good steel. This metalline powder being moistn'd in the viol with a little of the menstruum, was afterwards drench'd with more; whereupon the mixture grew very hot, and belch'd up copious and stinking fumes; which whether they consisted altogether of the volatile sulfur of the Mars, or of metalline steams participating of a sulfureous nature, and join'd with the saline exhalations of the menstruum, is not necessary to be here discuss'd. But whencesoever this stinking smoak proceeded, so inflammable it was, that upon the approach of a lighted candle to it, it would readily enough take fire, and burn with a blewish and somewhat greenish flame at the mouth of the viol for a good while together; and that, though with little light, yet with more strength than one would easily suspect.
  
  The word "sulfureous" may be somewhat confusing, especially since Boyle did a similar experiment with iron and sulfuric acid. However, in all likelihood, "sulfureous" should here be understood to mean "combustible".