Gas lighting explains why a large number of older gas lamps have been converted to electricity. Solar-rechargeable battery-powered gas light controllers can be easily retrofitted into existing gas lamps to keep the lights off during daylight hours and cut energy consumption and green-house gas carbon emissions by 50%. The use of natural gas (methane) for "indoor" lighting is nearly extinct. Besides producing a lot of heat, the combustion of methane tends to release significant amounts of carbon monoxide, a colorless and odorless gas which is more readily absorbed by the blood than oxygen, and can be deadly. Historically, the use of lamps
MAPP gas used, supplied in small to medium size containers. Blowtorches are used to brown and sear food cooked by low-temperature sous-vide techniques. Myhrvold recommends in "Modernist cuisine: the art and science of cooking" that MAPP gases should be used in preference to cheaper butane or propane as they produce higher temperatures with less risk of giving the food a gas flavour, as can happen with incompletely combusted gas. MAPP is colorless in both liquid and gas form. The gas has a pronounced acetylene-like or fishy odor at concentrations above 100 ppm, due to the addition of substituted amines as a polymerization