One of my earliest memories of industrial processes was as a child of hardly school age when my father, an engineer, toured me around his worksite - that of a w

One of my earliest memories of industrial processes was as a child of hardly school age when my father, an engineer, toured me around his worksite - that of a well-known gelatine manufacturer. The enduring and quite vivid memories that I still have of that visit are the overwhelming gut-wrenching stench of soaking animal hides† in a huge open-air pond almost the size of a swimming pool; the nearby huge pyramidal mountains of brilliant yellow sulfur that were well in excess of several stories high and which - unlike those in the accompanying photograph - were actually pointed at their tops; and finally, the big 'incinerator' and its huge tall 'recovery chimney' where the sulfur was burned to make SO2 thence sulfurous and ultimately sulfuric acid which is used in vast qualities in the manufacture of gelatine. (The 'chimney' was full of baffles over which water poured absorbing the SO2 as it went up the stack. Presumably, it was much cheaper for the manufacturer to make its own sulfuric acid than to buy it. The picture I tell is also indicative of the huge volumes of H2SO4 that were used in the manufacture of gelatine at the time. I don't know whether the same quantities are still used nowadays, perhaps the process is now more efficient, if so then please let me know.) Impressionable childhood memories like that aren't easily forgotten so I can well imagine what those pyramids of sulfur look like from close up. _ † Incidentally, my father managed to buy calf hides very cheaply from his work, they made very hard wearing floor mats for us kids to play on. They were still in good-to-excellent condition well into my adult years.