The difficulties encountered with the jelly-like precipitate found in carburetors are not new ones, as can be shown by previous carburetors and reports. Samples of this corrosion have been submitted from various aviation fields at different times. The purpose of this report is to determine the chemical content of a sediment often encountered in carburetors, to determine the cause of its formation, and to find a means of overcoming the difficulty. The bulk of all the deposits analyzed consisted of the oxide of aluminum in the various stages of hydration, from aluminum hyroxide to practically anhydrous oxide of aluminum. Most of the samples of corrosion were contaminated with organic matter, a small amount of sulphates, chlorides, carbonates, and the oxides of iron. The cause of this corrosion is attributed to the presence of water, which probably condenses in small droplets and, due to its higher gravity, finds its way to the bottom of the containers below the gasoline level.