Page:Philosophical Transactions of the Royal Society A - Volume 184.djvu/575

562 The experiments in Series I. were all made in the apparatus with variable volume.

Only two experiments are given of this series, and these two the last that were done with taps lubricated with a very stiff mixture of vaseline and paraffin. The ratios of the volumes of carbon dioxide and carbon monoxide to one another are interesting, being almost 1:1, when the excess of hydrogen is rather small, and 2:1 when the excess of hydrogen is much larger, recalling the results of experiments on limited oxidation of carbon monoxide.

These show how experiments failed frequently. They also led to the discovery that the fracture of the eudiometer was generally due to its being allowed to become too hot from the number of explosions following one another too rapidly, and then the cold mercury cracked the glass. The temperature at which they were performed was about 4° C. The ordinary glass taps were lubricated with syrupy phosphoric acid.

These experiments were made with the apparatus fitted with safety taps, and lubricated with phosphoric acid.

These experiments were the first made with dilute hydrochloric acid instead of dilute sulphuric acid, and it will be noticed that the ratio gradually falls from the first to the last of the four experiments, pointing out clearly that either the hydrogen is not the same or that the oxygen is not the same throughout, and that the impurity tends to increase or to diminish as the materials get used up. The first experiment of this series is the first in which the ratio exceeds 2:1.

The experiments in this series, especially the later ones, seem to indicate clearly that the low values found for the ratio were due to traces of chlorine escaping with the oxygen, even after passing through bulbs filled with pure soda, as the value rises except in the first case, after which potassium chlorate mixed with a little pure soda was used as the source of the oxygen.

Oxide of mercury was used instead of potassium chlorate as the source of oxygen when the value found is practically the same as in the later experiments of the last