The San Francisco call., 1898-07-10
0 Q 0 Q co Q Q 0 0 0 Q 6 6 0 6 oo

In one gram Q5 grains) of dust theres has been found 2,100.000 microbes.
 It has been calculated that in a city, like London man breathes in during, ten hours S 500 900 spores and germs. Itt IS needless to say that this immense num-s per of micro-organisms can have no ef-,, rect even If none of them are capable' or producing other than a mechanical: disturbance. It has been shown that, sterile dust injures the lungs, so to al greater extent should we look for injuryt from breathing these little seeds which, may develop and grow within the lung.
 The greater part of the dust of clean' room rooms. consisting of particles. derived, from mineral, vegetable and animal sub stances has little immediate effect upon health. However, 1t certainly tends to re- duce vitality and gives extra work to the breathing organs, so that it is extremely important that any one susceptible to consumption should be especially careful about breathing dusty air. beam of strong light shows the air of most inhab- fted rooms to be so crowded with dust as to be almost opaque to vision.
 The dust in the office of well-known physician of this city was found, on mil croscopical examination, to be largely of cotton and wool mold spores, bac- teria and finely divided sand from the street.
 Many living microbes float in the air of all dwelling houses. The air in rooms which are old, overcrowded and dirty contains great many disease germs. The walls of a room breathe in and out vast numbers of bacteria. In schools vast numbers of bacteria find lodging place under and between the boards of the floor if these are not close joined and well painted.
 Pathogenic or disease germs are nour- ished to great extent by the floors and walls of the rooms and for this reason they should be frequently cleansed with antiseptic solutions. The clothes of the scholars should be clean and washable and there should be no crowding in the classes.
 The foul smell of a crowded school room or a theater where all classes of society mingle is due in some measure from the dust that emanates from the walls and Is stirred up by shuffing feet, but mostly from the $50 grains of vapor and organic matter that is hourly eX- haled from the skin and lungs of each in- dividual in the room.
 This organic matter has very fetid smell and 1t contains epithelium cells and fatty matter from the mouth and phar ynx. This organic matter has been proved to be highly poisonous and caused the de- pression and faintness which always oc- CUTS with highly sensitive individual after a long hour in crowded house. This was the cause of the deaths in the Black Hole of Calcutta.
 In the sick the organic matter emanat- ing from the skin Is increased very off, fensive and contains great many bac- teria and particles of epidermis. This Will explain why actual contact WlIn the sick is unnecessary to "catch" the conta gious disease.
 Dust Is an accompaniment of many oc- equations, and its injurious effects de- pend upon its quality and upon the amount taken into the lungs.
 Metallic dust and dust containing gritty and hard silicious particles are the most injurious.
 Greenhow has calculated the mortality rate from pulmonary affections for the potters of Stake-upon-Trent He found a death rate from these affections for male inhabitants of 7.21 per 1000. as compared with a rate of 2.97 in healthy rural dis tricts. More than one-half of these deaths in Stake were in potters. although pot ters form only about one-thrd of the pop ulation of the place. This shows an ex- ceedingly high death rate from lung dis eases for potters and points to a special cause.
 Dr. Warman says of the potteries at Trenton. N. J.. that ''the work people suffer with phthisis. lead poisoning, rheu-