198 DETAILED SYNTHESIS. 



238. IN THE SECOND PLACE, IT HAS BEEN SHOWN that 



the active Tissues undergo changes by use, as do the 

 liquids and gases, and therefore the food taken must 

 correspond to the activity; and if the food cannot be had 

 or cannot be digested or otherwise prepared properly, 

 the activity of the tissues must be limited by the facts 

 existing. 



239. IN THE THIRD PLACE, IT HAS BEEN PROVED that 



food adapted to produce heat is different from that 

 adapted to nourish the tissues, and therefore should be 

 eaten abundantly when the Body is to be warmed, as in 

 cold weather, and sparingly in warm weather. 



Remark. IT MUST BE EVIDENT, from what has been said, that keep- 

 ing the Body properly clad and sheltered will prevent the escape of heat, 

 and save the necessity for a corresponding amount of food. Proper 

 clothing is therefore an economy. It will be equally advantageous to 

 apply the same deductions to the care of animals. Horses blanketed, 

 and cattle kept in apartments artificially warmed during cold weather, 

 are kept at less cost, and do better. A good digestion of a plentiful 

 supply of food is healthy ; therefore, the body should not be kept so 

 warm as not to need nor demand a good supply of food. 



240. IN THE FOURTH PLACE, IT HAS ALSO BEEN made 



to appear rational that the effete substances of the tissues 

 are in part burned or can be in the Body, so that activity 

 of the tissues is directly or indirectly a source of heat. 



241. IN THE FIFTH PLACE, IT HAS BEEN ARGUED that 



the Elements constituting food vary in proportions in 

 the same kinds, which are therefore of very various 

 qualities, and should be selected with care. 



Remark. IT WILL NOT BE UNWORTHY OF CONSIDERATION, as the pre- 

 vious chapters have proved, that the food necessary for furnishing the 

 Blood with its requirements may be obtained from different sources at 

 very different rates of expense. For example : starch, sugar, and fat are 

 calorific, and there cannot be any appreciable difference in the amount 

 of heat that similar weights of each will prodjice. Starch is much the 

 cheapest, as it is more readily produced; but it requires additional 

 preparation in the body, and food must be used to supply the power re- 



289. What ? 289. What ? What most be evident? What said of horses 

 andeattle? 240. What? 241. What -? Remark. What ? 



