221 
1878.] to Health and Comfort . 
Somebody discovered burnt atoms of dust in heated air, 
and its destructive, pernicious effect on the health was at 
once apparent ! But the comfort of the community some 
way overruled the theory, and hot-air furnaces, with ad- 
mitted deficiencies in quality of air, met greater favour than 
ever. It is allowed generally that the expensive steam- 
heating apparatus is at once the more pleasant, controllable, 
and durable ; and that the yet more expensive hot-water 
apparatus, with its great volumes of low temperature cur- 
rents of air, is the best of all means of heating. The cost 
in fuel by these several apparatuses becomes nearly the 
same, for equal effects, in warming of houses. 
The next demonstration was the chemical one. An 
occult effeCt is most conclusively, if not convincingly, ex- 
plained by an occult cause. Ozone is a favourable objeCt 
to carry a theory, and it really is possible, if we knew any- 
thing definite and certain about the origin or the effeCt of 
ozone ; some relation of this phenomenon of the requiring 
the evaporation of a small quantity of water, when heating 
air, might be traced. But no blinder pathway in science 
was ever opened than the ozone one. After this came De- 
ville and Troost’s discovery of the permeability of some 
metals, when heated at, or nearly at, red heat, to some of 
the gases. In the language of one of the most prominent 
writers on ventilation, this “ explains the very injurious and 
even poisonous effects produced by the use of stoves in the 
rooms of a dwelling ! ” 
The last resort of the unreasoning theoriser in physics is 
always to electricity, and efforts have not been wanting to 
show that either the presence or the absence of electricity, 
in some form or condition, ought to have something to do 
with the discomfort arising from heated air. The only 
answer to this hypothesis is, that heated air is equally 
oppressive in entire absence of water supply, whether highly 
eleCtrical or otherwise ; our vicissitudes of climate and of 
humidity enabling a test of eleCtric condition in extreme 
cases. There are times in any winter, in the Northern 
States, when it is possible to gather enough electricity, by 
walking over a carpet, to make the spark from the finger 
which will light a gas-light. The quantity of water de- 
manded at such times by a heating apparatus is no greater 
than at other times. There is not the least positive proof 
of relation of electricity to the healthfulness of air. Alto- 
gether, the whole resolves itself to the reiteration of the 
bare faCt that it is comfortable to evaporate a small quantity 
of water in heated rooms, and that it can be done without 
