Fire-places and Kitchen Utensils. 177 



nary processes, where the same degree of heat may be 

 had and be kept up without it, let a piece of meat be 

 cooked in a Papin's digester, which, as is well known, 

 is a boiler whose cover (which is fastened down with 

 screws) shuts with so much nicety that no steam can 

 escape out of it. In such a closed vessel, boiling (which 

 is nothing else but the escape of steam in bubbles from 

 the hot liquid) is absolutely impossible ; yet, if the heat 

 applied to the digester be such as would cause an equal 

 quantity of water in an open vessel to boil, the meat 

 will not only be done, but it will be found to be dressed 

 in a shorter time, and to be much tenderer than if it 

 had been boiled in an open boiler. By applying a still 

 greater degree of heat to the digester, the meat may be 

 so much done in a very few minutes as actually to fall 

 to pieces ; and even the very bones may be made soft 



Were it a question of mere idle curiosity, whether 

 it be the boiling of water, or simply the degree of heat 

 which exists in boiling water, by which food is cooked, 

 it would doubtless be folly to throw away time in its 

 investigation ; but this is far from being the case, for 

 boiling cannot be carried on without a very great expense 

 of fuel; but any boiling-hot liquid (by using proper 

 means for confining the heat) may be kept boiling-hot 

 for any length of time almost without any expense of 

 fuel at all. 



The waste of fuel in culinary processes, which arises 

 from making liquids boil unnecessarily, or when nothing 

 more would be necessary than to keep them boiling-hot, 

 is enormous. I have not a doubt but that much more 

 than half the fuel used in all the kitchens, public and 

 private, in the whole world, is wasted precisely in this 

 manner. 



