4.  Heating apparatus in buildings causing

damp places in walls.

5.  Salt-water drippings from refrigerator

cars.

6.  Brackish soil and sewage.

7.  Smoke and heated vapors issuing from

locomotives.

8.  Exposure to acid gases, vapors, or

liquids.

9.  Electrolytic action.

10. Electrolysis by  stray  currents from

street railways and other electrical

lines.

11. Decaying animal and vegetable

matter.

12. Damp, vitiated air in tunnels, subways,

covered  and confined places of  all

kinds.