186 THE CHEMISTKY OF CREATION. 



of this nature ; he was at that time travelling 

 in the Andes : " Our potatoes, after remain- 

 ing for some hours in the boiling water, were 

 nearly as hard as ever. The pot was left on 

 the fire all night, and next morning it was 

 boiled again, but yet the potatoes were not 

 cooked. I found out this by overhearing my 

 two companions discussing the cause ; they had 

 come to the simple conclusion, that the potatoes 

 were bewitched : or that the pot, which was a 

 new one, did not choose to boil them" The 

 monks of St. Bernard, living as they do at an 

 elevation of 8,600 feet, are sorely distressed at 

 the same phenomenon, and are compelled to 

 subsist almost entirely on fried, roasted, and 

 baked food in consequence of the water boiling 

 at so many degrees under the usual boiling 

 point, 212, as to render its heat insufficient to* 

 render wholesome the food which they procure. 

 It seems a great pity no kind traveller should 

 have carried a Papin's digester to them ; for as 

 that is a close vessel, fitted with a pressure valve, 

 they could easily remedy the inconvenience 

 under which they labour, by substituting an arti- 

 ficial pressure in place of the deficient atmospheric 

 weight. 



It is easily conceived, that since the density 

 of the air is directly proportionate to its 

 pressure, how important it must be for the 



