464 1 Dr. Ure on the ultimate analysis of 
it to the volume of dry gas, by help of the following table, 
computed by the well known formula from my table of the 
elastic force of steam, which the Royal Society did me the 
honour to publish in their Transactions for the year 1818. 
TABLE 
Tempera- 
ture. 
Multiplier. 
Tempera- 
ture. 
Multiplier. 
Tempera- 
ture. 
Multiplier. 
53 F- 
54 
55 
56 
57 
58 
59 
60 
O.987O 
0.0864, 
O.9858 
O.9852 
O.9846 
0 -9839 
0 -9833 
O.9827 
61 F. 
62 
63 
64 
65 
66 
67 
68 
6 9 
98.20 
9813 
98.06 
97-99 
97 93 
97.86 
97-79 
97-7 2 
97 - 6 5 
70 F. 
7 1 
72 
73 
0.9758 
0-9751 
0-9743 
0-9735 
In certain cases, where the quantity of hydrogen is small, 
or where, as in the example of indigo, its presence has been 
denied, I employ pulverulent proto-chloride of mercury ( ca- 
lomel) instead of peroxide of copper. The organic com- 
pound being intimately mixed with that powder, and gently 
heated, the muriatic acid gas obtained, demonstrates the pre- 
sence, though half of its volume will not give the total quan- 
tity of, hydrogen ; for a proportion of this elementary body 
continues associated with oxygen in the state of water. Dry 
oxalate of lead, treated in this way, yields not the slightest 
trace of muriatic acid, for on passing the disengaged gas 
through a dilute solution of nitrate of silver, no precipitation or 
