204 PHYSIOLOGY AND HEALTH. 



of this vapor to escape. And even then we find great relief 

 from frequently taking off the hat to air the head, or rather 

 to air the hat itself, by letting the enclosed air, which is 

 saturated with vapor, pass away, and fresh air take its place. 



CHAPTER V. 



Connection between the Skin and the internal Organs. Stomach, 

 Lungs, Muscles, &c. Effects of Cold on different People va- 

 rious. 



486. There is a very intimate connection between the 

 skin and the internal organs of the body. The blood flows 

 from one common centre through various channels to the 

 minute vessels of the skin, and all the parts included within 

 it. If the outer vessels are closed, and the circulation is in- 

 terrupted there, the blood must flow in greater abundance 

 into the inner vessels. On the contrary, if the inward flow 

 is impeded, it must find passage outwardly. In either case, 

 the balance of the circulation is disturbed, and the over- 

 burdened part is disordered. If we expose ourselves to 

 sudden or long-continued cold, the surface becomes chilled, 

 the cutaneous vessels contracted, the perspiration checked, 

 and then some of the internal organs bear the burden which 

 usually belongs to the skin. The check of the perspiration 

 is not the cause of the disturbance ; it is merely one of the 

 consequences of the previous interruption without, and a 

 sign of other troubles within. 



487. We have seen the influence of tea, taken into the 

 stomach, upon the cutaneous circulation and functions. 

 (441, p. 188.) Certain medicines, taken into the stomnch, 

 have the same effect. A man under the operation of an 

 emetic often sweats profusely. Some kinds of food, such 

 as shell-fish, when eaten, will cause the skin to break out 

 with the nettle rash. In some cases of indigestion, the same 

 effect is produced. In September, 1845, I saw a child 



