5G2 
DR. A. SCOTT ON THE COMPOSITION OF WATER BY VOLUME. 
The experiinent.s in Series I. were all made in the apparatus with variable volume. 
Series Ia. 
Only two experiments are given of this series, and these two the last that were 
done with taps lul^ricated with a very stiff mixture of vaseline and paraffin. The 
ratios of the volumes of carbon dioxide and caiTon monoxide to one another are 
interesting, being almost i : 1, when the excess of hydrogen is rather small, and 2 ;1 
when the excess of hydrogen is much larger, recalling the results of Bunsen’s experi¬ 
ments on limited oxidation of carbon monoxide. 
Series Ib. 
These show how experiments failed frequently. They also led to the discoverv 
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 v.dth syrupy phosphoric acid. 
Series Ic. 
These experiments were made with the apparatus fitted with safety taps, and 
lubricated with phosphoric, acid. 
Series Id. 
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. 
Se.ries Ie. 
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 Geisslee’s bulbs filled ^^uth 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. 
Series If. 
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 
