THE KIDNEYS. 161 



likely to take cold, except in very cold weather, if he contin- 

 ues active exercise till he can change the wet garments for 

 dry ones. Children do not often take cold from wading in 

 water so long as they are barefooted ; but if they get the 

 shoes and stockings wet, they are likely to take cold, for the 

 reasons above given. Many persons make a mistake in chan- 

 ging their winter underwear for summer too early. In most 

 of the Northern States it is not usually wise to do so until the 

 first of June ; but of course no definite rule can be laid down 

 in this matter. 



Sunshine. For good health we need sunshine. Of course 

 we get sunlight indoors, but so do many plants that drag out 

 a sickly existence. We need direct sunlight (when it is not 

 too hot), and many an invalid has been cured by sun-baths. 

 Part of the beneficial effects of sea-bathing is due to sunshine. 

 It is a good thing that it is now the fashion to take a vacation 

 and get well tanned. One of the benefits of the resorts of 

 Colorado (in addition to the climate's mildness) is that there 

 are very few cloudy days during the year. 



THE KIDNEYS. 



One important part of the work of the lungs, as we have 

 seen, is to throw out carbon dioxid. The skin also throws off 

 certain wastes. The kidneys have the special task of excret- 

 ing a waste product of the body called Urea. Urea is the 

 nitrogen-containing waste. 



The kidneys are attached to the dorsal wall of the abdom- 

 inal cavity. The depression of the kidneys corresponding 

 to the stem scar on a bean is called the Hilum. From the 

 hilum issues a white tube, the Ureter, which conveys the 

 urine to the bladder. Entering the kidney alongside the ureter 



