1) Absorption of oxygen was studied with eight kinds of materials, i.e., distilled water, sperm oil, sperm whale body oil, blue whale oil, olive oil, camellia oil, castor oil and liquid paraffin.
2) Decrease in pressure, ΔP, caused by absorption was measured punctually with lapse of time at constant volume and constant temperature of 35 ± 0.05°C. at variable pressure levels up to about 3 atm.
3) Decrease in volume was computed from ΔP. It was reduced to standard state and designated by ΔV0 , which represents the amount of oxygen absorbed by the liquid materials.
4) The solubility of oxygen was found to be directly proportional to pressure, namely, the relation A=cP, holds in every of the materials studied, where A is solubility, P, pressure and c, the proportional constant.
5) The solubilities of oxygen in various materials were compared in terms of A/ P. Within the oils and oily substances, the values of A/ P do not differ so greatly from each other and are 5.5 to 6 times as great as A/Pin water.
6) Some comparison was made between the value of A/P for oxygen and that for nitrogen or carbon dioxide. The ratio of solubility of the three gases (C02 : 0 2 : N 2) averages 15: 1. 7: 1 in the oily materials, and is 45: 1.8: 1 in water.
7) As for the absorption rate, the relation, ΔV0 =A(l-e-αt), holds for the absorption of oxygen by each liquid material.
8) The initial absorption rate for oxygen was compared in terms of αA/ P. It is greater in waxes than in glycerides or in water. αA/P in sperm oil (the greatest) is 16 times as great as that in castor oil (the smallest) and some 7 times as great as that in water.
9) Comparison was made between the "early absorption rate" for oxygen and that for nitrogen or carbon dioxide. The early absorption rate for oxygen agrees with that for nitrogen in size in every material, but early absorption rate for carbon dioxide is of a very different order. It is 20 to 30 times as great as that for oxygen or nitrogen in the oily matters, and 200 times as great in water.
10) Experiments were made to ascertain whether oxidation of oils took place in the absorption tests.