126 THE HUMAN BODY. 



some gelatin, the latter derived from the connective tissues 

 of the muscle. The flavoring matters and salts make it decep- 

 tively taste as if it were a strong solution of the whole meat, 

 and the gelatin causes it to " set " on cooling, so the cook 

 feels quite sure she has got out " all the strength of the meat/' 

 whereas the beef tea so prepared contains but little of the 

 most nutritious proteid portions, which in an insipid shrunken 

 form are left when the liquid is strained off. Various pro- 

 posals have been made with the object of avoiding this and 

 getting a really nutritive beef tea; as for example chopping 

 the raw meat fine and soaking it in strong brine for some 

 hours to dissolve out the myosin; or extracting it with dilute 

 acids which turn the myosin into syntonin and dissolve it and 

 at the same time render it non-coagulable by heat when subse- 

 quently boiled. Such methods, however, make unpalatable 

 compounds which invalids will not take. Beef tea is a slight 

 stimulant, and often extremely useful in temporarily main- 

 taining the strength and in preparing the stomach for other 

 food, but its direct value as a food is slight, and it cannot be 

 relied upon to keep up a patient's strength for any length of 

 time. There can be no doubt that thousands of sick persons 

 have in the past and are being to-day starved to death on it. 

 Liebig's extract of meat is essentially a very strong beef tea; 

 containing much of the flavoring substances of the meat, 

 nearly all its salts and the crystalline nitrogenous bodies, such 

 as kreatin, which exist in muscle, but hardly any of its really 

 nutritive parts, as was pointed out by Liebig himself. From 

 its stimulating effects it is often useful to persons in feeble 

 health, but other food should be given with it. It may also 

 be used on account of its flavor to add to the " stock " of soup 

 and for similar purposes ; but the erroneousness of the com- 

 mon belief that it is a highly nutritious food cannot be too 

 strongly insisted upon. Under the name of liqiiid extracts 

 of meat other substances have been prepared by subjecting 

 meat to chemical processes in which it undergoes changes 

 similar to those experienced in digestion: the myosin is thus 

 rendered soluble in water and uncoagulable by heat, and such 

 extracts if properly prepared are nutritious and can often be 

 absorbed when meat in the solid form cannot be digested: 

 they may thus help the stomach over a crisis, but are not, 

 even the best of them, to be depended on as anything but 

 temporary substitutes for other food; or in some cases as use- 

 ful additions to it. 



