Some of the gas connections use reverse (left-hand) threads to avoid disastrously mistaken connections. In welding kits, oxygen is connected with a right-hand thread, while acetylene and other flammable gases are connected with a left-hand thread. ¹⁾

Jan Baptista van Helmont (1579 or 1580 - 1644) - Flemish physician, physiologist, and alchemist who demonstrated the existence of various gaseous substances, including carbon dioxide. He is the originator of the term “gas”, a model of the Greek χάος 'cháos'. His theory of 'ferments' as triggers of physiological processes foreshadowed the discovery of substances now called enzymes. Helmont is believed to have begun the transformation of alchemy into chemistry. However, he did not reject mysticism and believed in the existence of the philosopher's stone. ²⁾

The second-largest producer of natural gas in Europe is the Netherlands. 50% of the gas produced in the Netherlands comes from the Groningen gas field, which is the largest in Europe and the tenth-largest in the world. The remaining 50% comes from the production of some 300 smaller gas fields, mainly scattered in the North Sea. ³⁾

Iodine occurs naturally in solid form - as a shiny, blue-black crystalline substance. When heated, by sublimation, it can change from a solid to a gaseous state. ⁴⁾

Uranus' atmosphere is about 83% hydrogen, 15% helium, 0.01% ammonia, and 0.00001% acetylene. ⁵⁾