Page:The chemical history of a candle.djvu/137

pint of nitrogen weighs 10 4/10 grains, or a cubic foot weighs 1 1/6 ounce. That is the weight of the nitrogen. The oxygen is heavier: a pint of it weighs 11 9/10 grains, and a cubic foot weighs 1 3/4 ounce. A pint of air weighs about 10 7/10 grains, and a cubic foot 1 1/6 ounce.

Fig. 25.

You have asked me several times, and I am very glad you have, "How do you weigh gases?" I will shew you; it is very simple, and easily done. Here is a balance, and here a