78 THE HUMAN BODY. 



make it deceptively taste as if it were a strong solution of 

 the whole meat, whereas, it contains but a small propor- 

 tion of the really nutritious parts, which are chiefly left 

 behind in tasteless shrunken shreds, when the liquor is 

 poured off. Some things dissolved out of the meat make 

 beef tea a stimulant to the nervous system and the heart, 

 but its nutritive value is small, and it cannot be relied upon 

 to keep up a sick person's strength for any length of time. 



Liebig's extract of meat is essentially but a concentrated 

 beef tea; from its stimulating effect it is often useful to 

 persons in feeble health, but other food should be given 

 with it. It contains all the flavoring matters of the meat, 

 and its proper use is for making gnivies and flavoring 

 soups; the erroneousness of the common belief that it is 

 a highly nutritious food cannot be too strongly insisted 

 upon, as sick persons may be starved on it if ignorantly 

 used. 



Various meat extracts are now prepared by subjecting 

 beef to chemical processes in which it undergoes changes 

 like those experienced in digestion. The myosin is thus 

 made soluble in water and uncoagulable by heat, and a real 

 concentrated meat extract is obtained. Before relying on 

 any one of them for the feeding of an invalid, it would, 

 however, be well to insist on having a statement of its 



Why does beef tea taste as if all the " strength " of the meat were 

 in it? Where do the chief nutritious parts remain when beef tea is 

 strained off the meat? What is the action of beef tea on the system ? 



What is Liebig's extract of meat ? Why is it sometimes useful to 

 invalids? What should be given them in addition? What is its 

 proper use? Why is it important to know that it is not a nutritious 

 food? 



How are some other meat extracts made? How is the myosin 

 changed in preparing them? Are they all to be relied on indiscrimi- 

 nately? What should be done before trusting the nutrition gf a 

 feeble person to any one of them? 



