XVili. ABSTRACT OF PROCEEDINGS. 
conditions the quantity of the gases of the atmosphere 
dissolved in the tissues of the body increases with the 
heightened pressure. The amount of gas in solution in the 
different tissues varies. Vernon has drawn attention to 
the increased solubility of nitrogen in fats and oils. Tissues 
containing much fat will therefore dissolve more gas than 
tissues with little fat. The pressure, as such, has little 
influence on the bodies of animals. Forms with the most 
delicate structure abound in the great oceanic depths, at 
which the pressure may be tons to the square inch. 
Poiselle, many years ago, shewed that the circulation in 
the web of the frog’s foot continued when the atmospheric 
pressure was 120lbs. to the square inch. Langley and 
Priestley have shewn that the tension of carbon dioxide in 
the alveolar air of the lungs, is maintained at a constant 
level. This tension determines the depth and rate of 
breathing. In diving the tension of carbon dioxide in the 
helmet is allowed to increase. It follows that the quantity 
of air pumped through the helmet must be increased with 
the heightened pressure in the helmet. The dyspnoea 
experienced by the diver is due to inattention to this venti- 
lation. At 210feet depth Damant experienced no respira- 
tory troubles with the necessary supply of air. Upon 
release from compressed air, various symptoms are experi- 
enced. These vary in degree from slight or severe pain to 
paralysis and death. They constitute “‘ bends ’’ and diver’s 
palsy. Bert, Schrotter, Hill and others have shewn that 
these phenomena result from the liberation of bubbles of 
gas in the tissues. Decompression must be carried out at 
such a rate that the dissolved gases can escape from the 
tissues slowly. Im diving, Haldane has shewn that the 
diver should be lowered quickly and raised in stages. The 
time spent at each stage of the ascent should depend on 
the degree of saturation of the tissues. The limit of com- 
pression is related to the amount of oxygen in the com- 
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