Page:Philosophical Transactions of the Royal Society A - Volume 184.djvu/577

564 the residues were very large, so large that the results were absolutely valueless, the non-absorbable residue amounting to many cubic centimetres in Experiments IX. and XI. It is therefore advisable to neglect also Experiments VIII., X., and XII., the results of which are somewhat abnormal. No reason can be given for the abnormal behaviour of all five experiments, but being all consecutive there is no doubt that some common source of impurity infected all five.

The first experiment was made with the last lot of hydrogen from a charge of sodium; fresh sodium was added, and the second experiment was made with the hydrogen at first given off. Both these results are high. The next three agree wonderfully with one another and are, as it were, made with the purest hydrogen obtainable from sodium, any impurity which would come off first being used in Experiment XXI., and any which tended to remain being left behind, and was rejected as not quite enough sodium remained to give hydrogen for another experiment. The gases were in the last three experiments also perfectly pure as far as residual gas was concerned. The silver oxide in this series and the next was the same sample and prepared from silver sulphate and potassium hydrate.

This series as a whole is the best which has been done, the gases being throughout pure, with the exception of very small impurity in the first experiment. They agree remarkably with one another, whether the hydrogen or the oxygen was in excess. The whole twelve experiments were successful without exception, and were all that could be performed with one charging of the palladium.

The values deduced from the various series are given below and together so that they may readily be compared. The equations employed in their reduction are the following well known ones:—

1. For the probable error of the arithmetical mean