PHYSIOLOGY IN THE STUDY OF DISEASE 89 



nately here nature pointed to some of the measures 

 which should be taken. What the sufferer com- 

 plained of was thirst and cold ; what he craved 

 for were water and warmth. 



In slight cases these were sufficient to save 

 life — for the reasons we shall presently discuss, — 

 but in many cases they were insufficient, and in 

 spite of them the patient died. 



The condition of " shock " or collapse was by no 

 means unknown. Surgeons were already familiar 

 with it in operations, chiefly upon the abdomen, 

 and physiologists had made some attempts to 

 elucidate it. 



But now the demand was for definite knowledge 

 immediately. A committee of physiologists was 

 formed under the Medical Research Committee, and 

 in co-operation with physicians and surgeons they 

 got to work. Soon it became manifest that the 

 prime cause of the condition is a failure in the 

 circulation of the blood, so that it no longer carries 

 the all-important oxygen to the tissues of the body. 

 Here again, as in gassing, the danger is death from 

 want of oxygen to the tissues, but in this case not 

 from a failure of oxgyen to get to the blood, but 

 from a failure of the blood to carry the oxygen to 

 the tissues. 



What is the cause of the failure ? 



You all know that water flows from a point of 

 high pressure to a point of low pressure. The flow 



