AIR AND VENTILATION. 93 



its bad effects." Unpleasant as it is to dwell on such a subject, it 

 is yet true that the exhalations from the human lungs and skin, if 

 retained and not diluted with a continuous supply of oxygen (the 

 active agent in all disinfectants), are the most repulsive with which 

 we can come in contact. We shun the approach of the dirty and 

 the diseased; we hide from view matters which are offensive to 

 sight and smell ; we carefully eschew impurities in our food and 

 drink, and even refuse the glass that has been raised to the lips of a 

 friend. But at the same time we resort to places of assembly and 

 draw into our lungs air loaded with effluvia from the lungs and 

 skin and clothing of every individual in the promiscuous crowd ; 

 exhalations offensive to a certain extent from the most healthy indi- 

 viduals, but, rising from a living mass of skin and lung in a state 

 of disease and prevented by the walls and ceiling from escaping, 

 injurious and repulsive in the highest degree. 



Ventilation Essential The great practical inference is, 

 that the only means of preventing persons from poisoning them- 

 selves and others is to insure their being constantly surrounded by 

 fresh air; otherwise, low fevers may result, and such acute diseases 

 as scarlatina, measles, small-pox, etc., may be excited in epidemic 

 forms, often marked by malignant symptoms. The air of an apart- 

 ment containing several human beings, if unchanged, not only 

 becomes charged with carbonic-acid gas, but also, as before stated, 

 impregnated with animal particles which fly off from the skin and 

 lungs, so minute as scarcely to be detected by the microscope, 

 which taken by the breath into the lungs may be absorbed and 

 develop the worst forms of scrofula and consumption. But if these 

 particles are given off from persons affected ,with or recovering from 

 small-pox, scarlet fever, whooping-cough, typhus, etc., they will exert 

 a still more injurious influence upon the health, and probably gen- 

 erate again the diseases from which they emanated. 



Ventilation of Schools The sanitary arrangements of 

 many schools are notoriously bad. The buildings used for such 

 purposes are often unsuitable, and in space and windows very inad- 

 equate. This applies often both to the school-rooms and the sleep- 

 ing-rooms, which are over-crowded and badly ventilated, causing 

 loss of appetite, headaches and general delicacy effects often 

 attributed to overwork, but in reality due to want of fresh air. Parents 

 should always inspect the rooms and ascertain their size, the posi- 

 tion of the windows and fireplaces and other facilities for ventila- 

 tion, with the average number of occupants. A rough but sug- 

 gestive test of the ventilation of a school-room may be secured by 

 entering it after it has been occupied some two hours, and compar- 

 ing the difference between the air of the room and that out of 

 doors. 



Badly Ventilated Churches, etc. It is important to 

 remember that an assembly in an ill-ventilated church, court of law, 

 school-room, theatre, ball-room or evening party may include some 



