606 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1911. 
drains. It may be worth while for the housebuilder to satisfy him- 
self of the character of the plumbing, as of the character of the mortar, 
but compulsory inspection by public officials is hardly warranted 
on the ground of a high degree of demonstrated danger to the public 
health. It is certain, too, that the enforced installation of immensely 
complicated and elaborate piping and trapping systems simply adds 
to the cost of building without any compensating hygienic advan- 
tages. The plumbing ordinances of our large cities often contain 
inconsistencies and contradictions, what is required in one city 
being sometimes forbidden in another. <A revision and simplifica- 
tion of municipal plumbing regulations, a minimizing of official 
inspection, and especially an education of the public to the fact that 
diphtheria, typhoid fever, and scarlet fever have never been definitely 
traced to sewer air or bad plumbing are reform measures that might 
release a considerable sum of public money for use in really profitable 
lines of sanitary endeavor. 
In the matter of heating and ventilation enormous sums have 
been spent and are being spent to renew the air in rooms and 
public assembly halls and to introduce pure air in what has been 
assumed to be necessary amounts. And yet if the work of Beu,? 
Heymann, Paul, Erclentz, Fligge,? Leonard Hill, and others means 
anything, it demonstrates that the whole effect from bad air and 
crowded rooms is due to heat and moisture and not to carbon dioxide 
or to any poisonous excretions in expired air. When all the effects 
of crowd poison upon a group of individuals in an experimentally 
sealed chamber can be eliminated by rapidly whirling electric fans, 
it is useless any longer to look upon carbon dioxide as a measure of 
danger. If we recoginze that all the discomfort from breathing air 
in a confined space is due to a disturbance of the thermal relations 
of the body, the problem of ventilation becomes very different from 
what has usually been supposed. In temperate climates, at all 
events, it ought to be much simpler to provide for proper heat regula- 
tion of the body than to warm a large volume of outside air and 
introduce it into a building continuously or at stated mtervals. It 
may well be asked whether the elaborate legal regulations governing 
the supply of air and the cubic feet of bedroom space:have a real 
basis in scientfic knowledge. If overheating, moisture content, and 
stagnation of the air are the chief things to be avoided, may this 
end not be reached more effectively and less expensively than by 
present methods ? 
One conspicuous function at present required of or voluntarily 
exercised by health departments is the practice of terminal disinfec- 
tion after cases of infectious disease. This has come to play a large 
1 Zeitschr. Hyg., 1893, vol. 14, p. 64. 2 Zeitschr. Hyg., 1905, vol. 49, p. 363. 
