53 
that I burn on an average, through 5 or 6 jets per evening 
89,00 cubic feet per quarter. This contains 890 grains of 
sulphur, which is equal to 2,670 grains of sulphuric acid 
(H 2 S0 4 ) ; so that I turn into the atmosphere of my house, 
mostly into one room, nearly 6 ounces of sulphuric acid in 
three months. This is 24 ounces, or 1 j pounds per annum. 
Now if I had been burning the Leeds gas, of the quality 
which has recently been subjected to a good deal of criticism, 
and which is stated to contain 40 grains per 100 cubic feet, 
then I should be subjecting the contents of my house to the 
action of 1 jibs, of vitriol per quarter, or 61bs. per annum 
In many cases, certainly in those cases where the contents 
of the room are most liable to damage, the above amount of 
gas, namely that from 5 or 6 lights, is given off into the 
atmosphere of one room. 
Almost all the objects in the upper parts of a room are 
susceptible to damage by the vapour of sulphuric acid. I 
do not take into consideration the presence of sulphur 
dioxide, for it is almost impossible that this body could 
escape conversion into sulphuric acid in a very short space 
of time, in the presence of oxygen, the vapour of water and 
heat. Ceilings, cornices, wallpapers, pictures, with their 
cords or chains, and frames, books, and so on, are all objects 
which are susceptible to the corrosive action of the vapour 
of sulphuric acid, and there cannot be much doubt that in a 
longer or shorter time they will all suffer from the presence 
of the sulphur in gas where the latter is burned in any 
quantity. The great danger in the action of sulphuric acid, 
in these cases is that it is a cumulative one. Its action will 
be accumulative in a longer or shorter time under the fol- 
lowing conditions respectively, burning the same amount of 
gas in each case. In a longer time if the ventilation is very 
good, and the walls of the apartment perfectly free from 
any dampness. In a shorter time when these two condi- 
tions are unfavourable, especially when the walls or portions 
