ADAPTATIONS 



the Arctic Ocean or in the hottest regions 

 of the world. The Esquimaux live where, 

 during the long winter, the air is from 

 128 to 148 degrees colder than their blood, 

 while the people of Zanzibar live for 

 months where the air they breathe is 20 

 degrees warmer than their blood. More 

 than a hundred years ago Dr. Blagden, 

 president of the Royal Society, and Dr. 

 Fordyce, F.R.S., stayed for twenty min- 

 utes in heated ovens which cooked a beef- 

 steak in 13 minutes, without the normal 

 heat of their blood meanwhile varying in 

 the least. They reported that their watch 

 chains were then too hot to touch, while 

 the air which they exhaled from their lungs 

 felt refreshingly cool. 



Nothing, indeed, but internal derange- 

 ments can change the normal temperature 

 of the blood, and hence the value of the 

 clinical thermometer in disease. But to 

 explain fever itself pathologists have la- 

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