[Footnote: Abstract of a lecture before the Master Plumbers'
Association, New York, Nov. 2. 1882.]
By Prof. C. F. CHANDLER.
It is only about one hundred years since the first important facts were
discovered which threw light upon the chemistry of atmosphere. It was in
1774 that Dr. Priestley, in London, and Scheele, in Sweden, discovered
the vital constituents of the atmosphere--the oxygen gas which supports
life. The inert gas, nitrogen, had been discovered a year or two before.
When we examine our atmosphere, we find it is composed of oxygen and
nitrogen. The nitrogen constitutes no less than 80 per cent, of the
atmosphere; the remaining 20 percent, consists of oxygen, so that the
atmosphere consists almost entirely of these two gases, odorless and
colorless and invisible. The atmosphere is, however, never free from
moisture; a certain amount of aqueous vapor is always present. The
quantity can hardly be stated, as it varies from day to day and month
to month; it depends upon the temperature and other conditions. Then
we have the gas commonly called carbonic acid in extremely minute
quantities, about one part in 2,500, or four one-hundredths of one per
cent. A small quantity of ammonia and a small quantity of ozone are also
present.
Besides these gases which have been enumerated, and which play an
important part in supporting life in both the kingdoms of nature, we
find a great many solids. Every housewife knows how dust settles upon
everything about the house. This dust has recently been the subject of
most active study, and it proves to be quite as important as the vital
oxygen that actually supports life. When we examine this dust--and it
falls everywhere, not only in the city streets, but upon the tops of
mountains, upon the deck of the ocean steamer, and the Arctic snow--we
find some of it does not belong to the earth, and, as it is not
terrestrial, we call it cosmical. And when it falls in large pieces we
call it a meteorite or shooting star. When the Challenger crossed the
Atlantic, and soundings were made in the deep sea, in the mud that was
brought up and examined there were found various little particles that
were not terrestrial. They were dust particles that were dropped into
the atmosphere of the earth from outer space. Then we have terrestrial
dust, and we divide that into mineral and organic. The mineral consists
chiefly of clay, sand, and, near the ocean, salt. Then we have organic
matter. Some of this is dead leaves which have been ground to powder.
Animal matter has also become dry and reduced to powder, and we actually
find the remains of animals and plants floating upon the atmosphere,
especially in the city. Examinations of the dust which had collected
upon the basement and higher windows of a Fifth avenue residence showed
that the dust upon the basement floor was chiefly composed of sand.
And the higher up I went, the smaller proportion of sand and a larger
proportion of animal matter, so that the dust that blows into our faces
is largely decomposing animal substance.
But we have a living matter in the atmosphere. We often notice in the
summer, after a rain, that the ground is yellow. On gathering up the
yellow powder and examining it under the microscope, we find that it
consists of pollen. The pollen of rag weed and other plants is supposed
to be the cause of hay fever. But we also have something far more
important in the germs of certain classes of vegetation. The effects
are familiar. If food is put away, it becomes mouldy. This mould is a
peculiar kind of vegetation which is called a fungus, and the plants
fungi. In order for this mould to develop a certain temperature and a
certain degree of moisture are necessary. Our food, we say, decays.
Now, what we call decay is really the growth of these fungi. Animal and
vegetable substances which these fungi seize upon are destroyed. All
ordinary fermentations and putrefactions are due to mould fungi, yeast
plants, or bacteria, and liquids undergoing these processes carry these
fungi and their germs wherever they go. The refuse of the city pollutes
the air. You have only to pass along any street to find more or less
rubbish. That furnishes the nidus for the growth and development of
these germs, and until we adopt better methods of getting rid of that
refuse, we never shall have the air of this city in the condition that
it should be.
One of the most constant sources of the pollution of the air in
inhabited localities is the decomposition that takes place in the
ground. Refuse of every kind gets into it. Our sewers are leaky, and
putrefaction is constantly going on. The soil down to the limit of
the ground water contains a large amount of air. This air, when the
atmospheric pressure in the house is diminished, is drawn in with such
organic impurities as it contains. A cement floor in the cellar is not
a protection against this entrance of the ground air, for the cement is
porous to the passage of air, but a remedy may be found by laying on the
cement a covering of coal tar pitch, in which bricks are set on edge,
the spaces between the bricks are filled with the melted pitch, and the
bricks then covered with coal tar pitch. When the house is building, the
foundation walls should also be similarly coated, outside as well as
inside. Such a cellar floor was considered to be absolutely impervious
to ground air and moisture. The lecturer had recently laid this floor in
his own house with the greatest success. The atmosphere of the entire
house is improved, and the expense is very moderate. Another source of
the contamination of the air of houses is the heating apparatus.
Stoves and furnaces, however well constructed at first, will, from the
contraction and expansion of the metal, soon allow the escape of coal
gas, and this danger is greatly increased by the use of dampers in
the stove-pipe. When, to regulate the fire, the damper in the pipe is
closed, the gases, having their passage to the chimney cut off, will
escape through any cracks or openings in the stove into the room.
Prof. Chandler, having kept a record of accidents from this cause, had
accumulated a formidable list of suffocations due to the use of the
damper. The danger was now somewhat lessened by providing dampers with
perforations in the center, which allowed the gases to escape when the
damper was closed. As regards the maintenance of pure air in houses,
the preference was given to the open fire-place. The hot-air furnace
deriving a supply of pure air from out of doors was, when properly
constructed, a very satisfactory method of heating, but in city houses
the mistake was often made of carrying the cold air duct of the furnace
to the front of the house, where it was exposed to the dust of the
streets. It should be taken from the rear end of the house, and carried
some distance above the surface of the yard. It was an excellent
expedient to insert in the cold air duct a wire screen to hold a layer
of cotton to retain the floating impurities which might enter the
air-box. This could be removed from time to time, and the cotton
replaced. Steam heating has been objected to by many for reasons in
no wise due to the apparatus, but to neglect in the use of it. The
complaint of closeness where steam is used is due to the fact that a
room containing a steam radiator can be heated with every door and
window closed, and no fresh air admitted, while with stoves and open
fire-places a certain quantity of fresh air must be admitted to maintain
the fire. Where radiators are used, the ventilation of the rooms should,
therefore, be looked after. Again, the complaint that steam apparatus
has an unpleasant odor is due to the fact that the radiators are allowed
to become covered with dust, which is cooked, and gives rise to the
smells complained of. The radiator should be from time to time
cleaned. When these precautions are taken, no means of heating is more
satisfactory than steam.
Sewer gas is another source of contamination; this is a very indefinite
term, to which formerly many false and exaggerated properties of causing
specific diseases were attributed. It is now, however, recognized to
mean simply the air of sewers, generally not differing very greatly from
common air, containing a certain proportion of marsh gas, carbonic
acid, and sulphureted hydrogen, etc. No one of these gases, however,
is capable of producing the diseases attributed to sewer gas. Careful
research has shown that it is the sewage itself, containing germs of
specific disease, which is added to the air in the sewer by the breaking
of bubbles of gas on its surface, which is the cause of the diseases
associated with sewers.
An intimate connection is believed to exist between the germs of sewer
air and diphtheria, and probably also between sewer air and scarlet
fever. This sewer gas is to be excluded from our houses by proper
systems of plumbing, and to such an extent have these now been
perfected, that there is no objection to having plumbing fixtures in
all parts of the house. This opinion has lately been objected to in the
_Popular Science Monthly_, as it was at a meeting of the Academy of
Medicine last spring, but on wholly insufficient grounds.
The objectors all insist that a trap will allow sewer gas to pass
through it, and the experiments made at the Academy of Medicine showed
that sulphureted hydrogen gas, etc., would so pass. The advocates of the
trap have never denied that the water seal would absorb gases on one
side and give them off on the other, but they do deny that, in the
conditions existing in good plumbing, such gases will be given off in
quantities to do any damage, and they confidently assert that the germ
which is the dangerous element will not pass the seal at all. Pumpelly
investigated the matter for the National Board of Health, and in no
instance was he able to make the germ pass the seal of the trap. It is
now proposed to set up against the weight of this scientific testimony
the results of an investigator in Chicago, whose work was at once
appropriated as an advertisement by stock jobbing disinfectant companies
in a manner which raises a suspicion that the investigation was made in
their interest. He described tersely the essentials of good plumbing,
the necessity of a trap on the house drain, the ventilation of the
soil-pipe, and the ventilation of the trap against siphonage. Of the
first, he said that it offered protection to each householder against
the entrance into his house of the germs of a contagious disease which
passed into the common sewer from the house of a neighbor. Were the trap
dispensed with, the contagion in the sewer would have free entrance into
the houses connecting with it.
Prof. Chandler, in conclusion, alluded to the cordial relations now
existing between the Board of Health and the majority of the master
plumbers of the city. He said that for himself his opinion of the craft
had greatly risen during his intimate connection with plumbers the last
two years. He thought the majority of the jobs now done in the city are
well executed. He believed that the Board of Health had not been obliged
to proceed against more than eight master plumbers since the new law
went into force. He called upon the Association to adopt a "code of
ethics," which should define what an honest plumber can do and cannot
do, and he illustrated his meaning by citing an extraordinary case of
fraudulent workmanship which had been recently reported to him. His
remarks on this point were greeted with frequent outbursts of applause.
* * * * *