NUTRIENT MATTERS PEE-EXIST IN PLANTS. 37 



slowly evaporated, there come on its surface skins of a body having the 

 same qualities as casein ; so fibrin, albumen, and casein pre-exist in plants. 



Fatty matters of every description may also be extracted from vege- 

 table products. From leaves, seeds, bark, wood, etc., oleaginous bodies 

 can be obtained by the action of sulphuric ether, which removes the fat, 

 and leaves it on subsequent evaporation. 



It being thus understood that the food of the graminivorous animals 

 contains nitrogenized bodies and fats ready formed, we have clearer views 

 of the function of digestion in those tribes. It is not necessary to im- 

 pute to their digestive organs the power of creating flesh and fat from 

 vegetable matter. The office of the animal is merely to collect. The 

 two groups being compared together, the carnivorous animal receives un- 

 der less compass the required amount of nutrition, and its digestive ap- 

 paratus is more compact. But the graminivorous animal must all the 

 day long collect large quantities of food, out of which it may extract the 

 little nutrient matter they contain. The carcass of an animal, seized by 

 a lion, is almost all digestible, but it would require a very large amount 

 of herbage or of grain to be supplied to an ox to make up the same quan- 

 tity of albumen .or fat. Hence the necessary complexity and size of the 

 digestive organs of the herbivorous group, and hence many of their hab- 

 its of life. 



Moreover, we see that even in this apparently extreme case the ani- 

 mal system does not clearly exhibit any quality of exerting Food formed 

 a formative action, nor of grouping atoms into a state of Destroyed by* 

 higher organization. It possesses no special power of mak- animals, 

 ing flesh. To the vegetable world we have to look as the great forma- 

 tive agent. In the organism of plants the various compounds wanted 

 by animals are fabricated. Animals destroy those compounds, and in 

 so doing maintain a high temperature, irrespective of atmospheric con- 

 ditions, and give rise to the phenomena of motion and intellectuality. 



Universal experience, as well as direct experiment, proves that in the 

 case of man health can not be maintained on a uniform diet, however it 

 may be with animals. A mixed food, which varies from time to time, 

 seems to be essential; and there can not be a doubt that the changes 

 which physicians have recognized in the nature of the predominating dis- 

 eases, from century to century, are connected with changes which have 

 taken place in the nature of the diet. The introduction of tea, coffee, 

 the potatoe, arid tobacco, must have made a marked impression in these 

 respects. 



Undue excesses of albumen, oil, or starch, in the diet of an individual, 

 produce a liability to arthritic, bilious, and rheumatic affec- Necessity of a 

 tions. An abstinence from fresh vegetables and fruits devel- ^an^us? * 

 ops scorbutic, and a deficiency of oleaginous materials scrofu- of cooking. 



