40 PHYSIOLOGY. 



Meat is noted for the large quantity of nitrogenous matter which it 

 contains, containing four times the amount of proteid compared with 

 the same weight of milk. The proteid in meat is myosin, the main 

 constituent. 



Beef-tea is a solution of gelatin, salts, extracted matters, a little 

 albumin, together with some fat. The value of beef-tea as an ali- 

 mentary substance has been much disputed, some claiming great 

 results from it, others none. However, one thing is certain; it 

 possesses a stimulant and restorative value, though it must not be 

 depended upon as a food and administered as such. 



LIEBIG'S BEEF TEA. It contains novain, oblitin, ignotin, and 

 neosin. Oblitin increases the tonus and peristaltic movements of 

 the intestine. It also increases the salivary secretion and lowers 

 arterial tension. Novain has a similar action to oblitin. Neosin 

 lowers the arterial tension. Neosin is also obtained from fresh muscle, 

 and is not due to putrefactive changes in beef-tea. 



The process of cooking meat loosens up the various fasciae and 

 enveloping membranes, thereby separating the fibers; at the same 

 time parasitic growths are killed. Thus the digestive juices are given 

 more ample opportunity for acting upon all parts of the foods, even 

 penetrating into the innermost parts. 



EGGS. 



The white of an egg is a faint-yellowish, albuminous fluid in- 

 closed in a framework of thin membranes, and this fluid itself is very 

 liquid, but seems viscid, because the membranes are entangled. Oval- 

 bumin, or the egg-albumin of the egg-white, is the chief constituent. 

 The mineral bodies in the white of the egg are potash, soda, lime, 

 magnesia, iron, chlorine, phosphoric acid, and sulphuric acid. 



The principal part of the yelk is an orange-yellow, alkaline emul- 

 sion of a mild taste. The yelk contains vitellin as its principal con- 

 stituent. Besides vitellin, the yelk contains alkali albuminate and 

 albumin. The yelk also contains a phosphorized fat (lecithin) with 

 cholesterin, fats, and a small quantity of sugar and of mineral bodies, 

 chiefly lime and phosphoric acid. Iron exists in the yelk in an or- 

 ganic combination. 



As the egg is so easily digested it is prized highly as a food. 

 However, the more that an egg is boiled, the more insoluble do the 

 proteids become and so are more indigestible. 



In cases where eggs are difficult of digestion the white of egg 

 may be given. In some persons the yelks of eggs cause headache and 



