THE -n'ONDEllFUL. 287 



without confusion or any fatal mixture. It is impossible to 

 understand how anything so perfect, and yet so minute can be 

 constructed at all, far less how it can be kept freely and rapidly 

 working, with such a material as blood passing through such 

 invisibly small tubes. No one knows how it is kept going ; man 

 has only lately discovered thut all this is actually accomplished ; 

 only lately discovered something of the deep meaning of the words 

 of David, " I am fearfully and wonderfully made." 



702. — "When we thus get a little idea of what the machine is, 

 we can at least easily understand what a little thing can obstruct 

 it, and how helpless we are to set it going again. The muscles 

 may rest, the nerves may rest, the brain may rest, the stomach 

 may rest, but the lungs can never rest. We can live some time 

 without food, and even without a new supply of water, but we 

 cannot live at all without a constant supply of air. And just as 

 we can in a thousand ways, spoil the natural air, but can never 

 improve it, so we can spoil the lungs, but can never improve 

 them by anything we can send into them. 



703. — There is only one way in which we can help the 

 lungs, and that is by calling on tiie skin to do some of their work 

 or more frequently by taking care that the skin does not leave 

 its own work for the lungs to do. The skin and the lungs should 

 both be at work purifying the same blood, and, roughly speaking, 

 each usually takes about the same quantity of waste material 

 out of the blood. Each breath that carries in oxygen carries out 

 its load of carbonic acid gas, water, and waste material, whilst 

 the skin is silently carrying off almost the same, so that any 

 failure on the part of the one puts more work on the other. 

 When the lung cells are closing, and consequently dying, as in 

 consumption, the skin tries to do double duty, as in the niiiht 

 sweats that mark that disease. When some of the pores of the 

 skin have been closed, as they are in what we call a common 

 •cold, each breath from the lungs is overloaded with the moisture 

 that the skin should have taken off. 



704. — Now it is dangerous to let the lungs do the work of 

 the skin, as well as their own, for a single hour. It is dangerous, 

 iind always permanently injurious, to call on the bowels, or the 



