, the products of combustion can be neglected and
with safety allowed to mingle with the atmosphere we are to breathe.

Scarcely a winter passes but one or more deaths are recorded from the
products of combustion given off from various forms of water heaters
used in bath rooms; scarcely a cookery class is given, with gas
stoves, that one or more ladies do not have to leave suffering from an
intense headache, and often in an almost fainting condition. And the
same cause which brings about these extreme cases, on a smaller scale
causes such physical discomfort to many delicately organized persons
that a large class exist who absolutely and resolutely decline to have
gas as an illuminant or fuel in any of their living rooms; and if the
use of gas, more especially as fuel, is to be extended, and if gas is
to hold its own in the future against such rivals as the electric
light, then those interested in gas and gas stoves must face the
problem, and by improving the methods of burning and using gas do away
with the present serious drawbacks which exist to its use.

The feeling has gradually been gaining ground in the public mind that,
when atmospheric burners and other devices for burning coal gas are
employed for heating purposes, certain deleterious products of
incomplete combustion find their way into the air, and that this takes
place to a considerable extent is shown by the facts brought forward
in a paper read by Mr. William Thomson before the last meeting of the
British Association.

Mr. Thomson attempted to separate and determine the quantity of carbon
monoxide and hydrocarbons present in the flue gases from various forms
of gas stoves and burners, but, like every other observer who has
attempted to solve this most difficult problem, he found it so beset
with difficulties that he had to abandon it, and contented himself
with determining the total amounts of carbon and hydrogen escaping in
an unburned condition, experiments which showed that the combustion of
gas in stoves for heating purposes is much more incomplete than one
had been in the habit of supposing, but his experiments give no clew
as to whether the incompletely burned matter consisted of such
deleterious gases as carbon monoxide and acetylene, or comparatively
harmless gases, such as marsh gas and hydrogen. After considerable
work upon the subject, I have succeeded in doing this by a very
delicate process of analysis, and I now wish to lay some of my resu