TREATMENT OF DECOMPRESSION SYMPTOMS 251 



of their work; the bell being then hoisted on deck can be slowly 

 decompressed. 



Fatigue brought on by over- work, bad ventilation, alcoholism, 

 oxygen-poisoning from long exposure to high pressure, or any 

 other cause which lowers the vigour of the circulation and respi- 

 ration, will delay the escape of the dissolved gas from the lungs, 



FIG. 18. Nitrogen Bubble in Brain of Mouse, compressing the 

 Cells of the Cortex (Finlayson, L. Hill, and MacLeod}. 



and increase the risk of the workers. The replacement of air by 

 oxygen in the air-lock previous to decompression would render 

 the process of decompression safe, and allow its execution in a 

 much shorter time. The 2 carrying power of the blood renders 

 the escape of much oxygen gas as bubbles impossible. Against 

 the use of this method is the deleterious effects which oxygen 

 produces on the lungs and central nervous system. It would be 



