THE HYGIENE OF NUTRITION 363 



to limit the number of occasions for resorting to 

 such means of relief. Most people can avoid recur- 

 rences by taking reasonable exercise, drinking a good 

 deal of water, and eating fruit and coarse vegetables. 



Washing out the colon now and then is a procedure 

 which has its devotees. It has a real value in special 

 cases, but is to be avoided unless prescribed by the 

 .physician. A dependence upon the enema may be 

 established which is in the highest degree irksome and 

 little better in principle than a cathartic habit. It may 

 be said incidentally that one marked difference between 

 the reaction to a purgative and an enema lies in the 

 fact that the drug usually contracts the output of the 

 kidneys by diverting water to the intestine, while the 

 enema encourages the absorption of water and increases 

 the volume of the urine. Irrigation of the colon is 

 accordingly helpful when it is desired to promote 

 elimination by the kidneys, as in some cases classed as 

 rheumatism and arthritis. 



Obesity. Increase of adipose tissue can occur only 

 when the income of the body is for some time in excess 

 of the fuel requirement. This is a plain fact, but one 

 which is not always recognized. It would seem to 

 follow that such increases could be counteracted either 

 by restricting the diet or by speeding up the oxidation. 

 Both objects are often sought. If the food is limited 

 the weight must diminish. When we are not eating or 

 drinking we are necessarily losing weight at the rate of 

 at least an ounce an hour. But fasting is not pleasant 

 and insufficient feeding may be even more distressing. 



The consumption of adipose tissue may be forced by 

 exercise. ' A common difficulty is that the appetite is 

 so stimulated that unless it is sternly curbed the accumu- 

 lation is at once replaced. The victim has his labor for 

 his pains. We have made a brief reference to the power 

 of thyroid extracts to accelerate the metabolism and to 

 the use of these preparations in medicines for weight 

 reduction. They are not ideal for the purpose since 





