242 BOILING VEGETABLES— ROASTING MEAT. 



of gelatine as a part of food is commonly overrated. 

 Its value consists chiefly in its being easily soluble, 

 and therefore more readily digestible, than albumen 

 or fibre. 



625. In boiling vegetables, very similar results are 

 produced ; the solid parts are softened and rendered 

 more soluble, whilst the albumen is coagulated. It 

 should always be borne in mind, that there is nothing 

 gained by heating the water very strongly so as to 

 make it boil rapidly ; but, on the contrary, it is 

 highly objectionable. Water which simmers, is very 

 nearly quite as hot as that which boils rapidly, and 

 does not carry off so much of the volatile principles 

 of the food. 



626. When it is desired to soften and dissolve food 

 as much as possible, pure soft water is best ; but 

 when it is designed only to soften, but not dissolve 

 it, hard water is preferable. In general, the solvent 

 powers of hard water are much less than those of 

 soft water. For this reason, pure soft water is best 

 for making soup, whilst hard water is best for boiling 

 joints of meat. Salt is constantly added to the 

 water used for cooking ; this diminishes its solvent 

 powers, rendering it harder, and therefore better 

 fitted for those operations which are intended to 

 soften the food, but not dissolve it. 



627. In roasting meat, the chemical changes pro- 

 duced are not very dissimilar from those effected by 

 boiling. A good deal depends on the management 

 of the fire ; if it is too hot at first, the outside of the 



