![]() ![]() Our results show that the isotopic composition of lake-water inputs is correlated with the isotopic composition of annual precipitation. To improve our understanding of lake-water isotopes, we analyzed the δD and δ 18O values of water from a hundred lakes in the western United States across a broad range of seasonal precipitation regimes. However, the effects of seasonal drought and the seasonal distribution of precipitation on lake-water isotopes are not well documented. If the operation be conducted over an inverted tube in which both poles are in the same tube, the oxygen and hydrogen will escape together gradually forcing the liquid out at the bottom of the tube.Lake-water isotopes can be used to track moisture regimes and water sources at present and in the geologic record. The result is that nothing is decomposed except pure water, so that pure hydrogen will be found in one arm of the apparatus and pure oxygen in the other. The addition of a few drops of sulphuric acid enables the current to pass, while at the same time the acid is not in danger of being acted upon appreciably by the electric current itself. Pure water is so poor a conductor of electricity that no decomposition will take place in the apparatus described because of the inability of the current to pass through the connecting arm filled with pure water between the positive and negative poles. If pure water with an electrolyte which cannot be decomposed is used the resulting gases will be pure. This form of simple apparatus is called by chemists an eudiometer. It will be seen that the volume of the hydrogen collected is just double that of the oxygen. The gases rise in the tube and are collected. The positive pole is marked + and is found to be giving off oxygen the negative pole is marked - and is found to be giving off hydrogen. This is illustrated in the simple apparatus shown in the figure. If the negative pole be placed in one arm of a bent tube and the positive pole in the other, the gases may be collected separately. If water containing an electrolyte such as diluted sulphuric acid is subjected to the action of the electric current hydrogen will be given off at the negative pole and oxygen at the positive pole of the electrical apparatus. The composition of water may be shown very beautifully and very easily by an experiment which produces its decomposition. The strongest containers of mixtures of hydrogen and oxygen in proportions to form water are ruptured with the greatest violence if the combination takes place. The union takes place on the application of a flame, with tremendous violence. If the composition of water is referred back to the gaseous state of its two components, it is found that two volumes of hydrogen combine with one volume of oxygen to form water. In nine pounds of pure water in round numbers eight pounds are oxygen and one pound hydrogen. Hydrogen does not exist very largely in a free state, though its occurrence in nature as hydrogen is sometimes observed. Oxygen forms practically one-fifth of the volume of the atmosphere. These materials in the free state exist only in a gaseous condition. Chemically pure water is composed of only two substances, hydrogen and oxygen. ![]()
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