section_path: Scholarly achievements/Other achievements in science and technology
section_name: Other achievements in science and technology
paragraph_text: Other achievements in science and technology
  
  Shen Kuo described the phenomena of natural predator insects controlling the population of pests, the latter of which had the potential to wreak havoc upon the agricultural base of China.
  
  Shen also wrote about advancements in metallurgy. While visiting the iron-producing district at Cizhou in 1075, Shen described the "partial decarburization " method of reforging cast iron under a cold blast, which Hartwell, Needham, and Wertime state is the predecessor of the Bessemer process. Shen was worried about deforestation due to the needs of the iron industry and ink makers using pine soot in the production process, so he suggested for the latter an alternative of petroleum, which he believed was "produced inexhaustibly within the earth". Shen used the soot from the smoke of burned petroleum fuel (石油 Shíyóu, "rock oil" as Shen called it) to invent a new, more durable type of writing ink; the Ming dynasty pharmacologist Li Shizhen (1518–1593) wrote that Shen's ink was "lustrous like lacquer, and superior to that made from pinewood lamp-black," or the soot from pinewood.