How joyously I breathe this pure air! As the autogyro moves forward, air blows upward across the rotor, making it spin. It would be just as incorrect to deny the permeability to air of the frozen soil as that of the Maltese rock. The rock of Malta has been proved by Leath Adams to suck up water on an average to one-third of its volume; consequently, when dry it must contain air to the same extent. This bird is shut up in the same way as workmen sometimes are, digging at a well or at some kind of shaft. In one litre of air there are about thirteen cubic inches of oxygen, which the bird would have consumed in ten hours. You cannot longer have any doubt about the motion of the air through gravel: but I want to convince your senses; I want you to see the motion of the air, and to see that motion taking place through a much thicker stratum of gravel than the strata shutting in the bird. In coastal areas fresh water may contain significant concentrations of salts derived from the sea if windy conditions have lifted drops of seawater into the rain-bearing clouds.

This well now provides approximately 1.5 lakh litres of water daily to the TMC, which pumps it to a sump tank near the Sonnappanahalli Panchayat office for distribution to areas such as Shaktinagar, Muneshwar Camp, and nearby wards. It is well known that water becomes solid at a temperature below freezing-point. What I have shown you in regard to gravel, can, in a similar way, be proved in regard to sand, clay, and even more solid stony and rocky soils. This gives a cubical space of 960 feet, which is not more than half the cubical space allowed each patient in our best-arranged hospitals. 134,400 cubic inches, or 77.77 cubic feet, of air expired by each sleeper during the night of eight hours. Can it then be a matter of surprise that death from diseased heart should so often occur during the night? 3.11 cubic feet of carbonic acid exhaled by each sleeper during the night. It therefore follows that, if no fresh air entered the room, and if in consequence the carbonic acid had no means of escape, the air of the apartment would, at the end of the eight hours of night, contain 1.29 per cent.

The bodies were buried in chalk, quarry, rubble, sand, argillite, slate, marl, or clay soils, and the sad work lasted from the beginning of March to the end of June. The cylinder is shut at its lower end by a wire netting, on which a stratum of gravel rests. As the processes of putrefaction and decay are intimately connected with the activity of certain lower organisms, which prey upon the dead, it is sufficiently clear that these organisms must thrive differently in different kinds of soil. In developed countries, tariffs are usually the same for different categories of users and for different levels of consumption. IF in the two preceding lectures I have tried to draw your attention to the penetration of the air into our clothing and our dwellings, I shall try in this last lecture to do the same in reference to the air which is in the ground, and to its connection and intercourse with the air above the ground. The warm air in the chimney is pressed into and up the chimney by the cold air surrounding the same. The chimney cannot act without heat, and the heat is only the means of disturbing the equilibrium of the columns of air inside and outside the chimney.

The warm air inside is lighter than the cold air outside; and this being so, the former must float upward through the chimney, just like oil in water. At all times and seasons-in the depth of winter-by day and by night-a patient suffering from a paroxysm of cardiac asthma will hurry to the open door or window, and there, with his body hanging half out, will remain, with scarcely any vestments upon him, breathing the cold air until the paroxysm has ceased. You see this high glass cylinder (Fig. 2), with a smaller glass tube inside, open at both ends. I remember that on one occasion I was summoned to a case which had occurred in a bedroom fifteen feet long, twelve feet wide, and eight feet high. Where this means is defective, but where, nevertheless, the vitiation of the air of the bedroom does not exceed 1 per cent. It is much to be feared that to this degree of vitiation the air of the bedrooms of the poor and of others not unfrequently rises by the too prevalent system of excluding fresh air, and by the frequent absence of provision for the escape of that which has already passed through the lungs.