and more widely installed for reasons of comfort and health. Yet the art was 

 first developed because variations in moisture and temperature sometimes 

 interfered with speed or quality of production in textile mills and in printing. 



In many industries it is impossible to prevent the formation of dirt of 

 various kinds, which may be injurious to the physical health of the workers. 

 In some industries the processes themseK'es call for a higher or a lower tem- 

 perature than is best for human beings. In many industries poisonous gases 

 and fumes are produced. Most acid fumes may "eat away" the delicate linings 

 of the lungs. Alcohol fumes and the fumes of other solvents used in varnishes, 

 phosphorus fumes, lead fumes, and other fumes are absorbed and so poison 

 the body. 



In certain occupations the worker is constantly exposed to injurious dust. 

 (1) Coal dust and the flufl from the fibers used in spinning and weaving may 

 crust or cover part of the lung lining. This reduces actual breathing surfaces 

 and lowers the resistance of the cells to disease microbes. (2) Hard, sharp par- 

 ticles of metal or stone and fine sand, or silica, may scratch the delicate linings 

 of the air sacs and expose them to the entrance of disease microbes. Such dust 

 is produced where metals or stones are ground, polished or chipped, and where 

 sandblasts are used. (3) Street and house dusts may carry disease germs of 

 various kinds. 



Intelligent managers long ago discovered that it was profitable from a 

 strictly business point of view to maintain working conditions that protected 

 the health of the workers and that made the surroundings pleasant and agree- 

 able. Most workers, however, were neither fortunate enough to select in- 

 telligent managers nor able, otherwise, to insist upon suitable conditions. 

 They were obliged, therefore, either to organize like other professional or 

 business groups and to use their joint influence to better the situation, or else 

 to wait patiently until the community was sufficiently sensitive and sufficiently 

 responsible to regulate working conditions through public agencies. 



In the course of years we have gradually developed public standards, and 

 set up machinery for enforcing standards in industrial and commercial estab- 

 lishments. These standards cover a wide range, ensuring a subsistence wage, 

 sanitary washrooms, suitable drinking-water, suitable places for meals, and the 

 removal of dusts, fumes and gases from the atmosphere. They include also pre- 

 vention of disturbing noises, provision of safety appliances, regulation of hours 

 of work, and prohibition of certain kinds of work to women and children. 



We know enough biology to raise the physical and mental well-being of the 

 entire population to a much higher level than that which the top quarter now 

 enjoys. We know also that from an economic point of view good health pays; 

 that is, it brings returns beyond anything that it may cost in money. But we 

 do not yet know how to organize our practical affairs so as to make full use of 

 our science for all the people. 



635 



