The strength of milk of lime quoted in the above table was obtained by carefully allowing 50 grammes of carbide to interact with 550 c.c. of water at 5° C. A higher degree of concentration of the milk of lime was found by Hammerschmidt and Sandmann to cause a slight decrease in the amount of acetylene held in solution by it. Hammerschmidt and Sandmann's figures, however, do not agree well with others obtained by Caro, who has also determined the solubility of acetylene in lime-water, using first, a clear saturated lime-water prepared at 20° C. and secondly, a milk of lime obtained by slaking 10 grammes of quicklime in 100 c.c. of water. As before, the figures relate to the volumes of acetylene dissolved at atmospheric pressure by 100 volumes of the stated liquid. _________________________________________________ | | | | | Temperature. | Lime-water. | Milk of Lime. | |_______________|_______________|_________________| | | | | | Degs C. | | | | 0 | 146.2 | 152.6 | | 5 | 138.5 | -- | | 15 | 122.8 | 134.8 | | 50 | 43.9 | 62.6 | | 90 | 6.2 | 9.2 | |_______________|_______________|_________________| Figures showing the solubility of acetylene in plain water at different temperatures have been published in Landolt-Börnstein's Physico- Chemical Tables. These are reproduced below. The "Coefficient of Absorption" is the volume of the gas, measured at 0° C. and a barometric height of 760 mm. taken up by one volume of water, at the stated temperature, when the gas pressure on the surface, apart from the vapour pressure of the water itself, is 760 mm. The "Solubility" is the weight of acetylene in grammes taken up by 100 grammes of water at the stated temperature, when the total pressure on the surface, including that of the vapour pressure of the water, is 760 mm.