A jacket having air-tight cells, or cavities which can be filled with air, to render persons buoyant in swimming.
2
A short glass jar fitted with an air-tight cover, and containing some desiccating agent, as sulphuric acid or calcium chloride, above which is suspended the material to be dried, or preserved from moisture.
3
Made perfectly close or air-tight by fusion, so that no gas or spirit can enter or escape
