362 POPULAR SCIENCE MONTHLY. 



the separate parts of tlie human frame. And it was not until 

 the early decades of the present century that science was able to 

 declare the ultimate element out of which all these varied parts are 

 built to be a tiny particle of living matter which was called a cell. 



Somebody has said of Turner that he was a man who thought 

 in paint. The modern devotee to medicine, if he seriously thinks 

 at all, must think in cells. Physicians used to think in symptoms, 

 and it took them a great many years to learn that they must think 

 also in cells and organs that is, with clear morphological concep- 

 tions if they would crystallize for use the knowledge which ex- 

 perience brought them. 



Through the long processes of evolution, these cells have 

 acquired peculiar forms, and adapted themselves to the perform- 

 ance of special functions. The great cell groups we call them 

 liver, lung, brain, muscle, bone each doing its particular work, 

 all act in harmony for the maintenance of the life and perform- 

 ance of the body as an independent being. 



We do not yet understand, nor shall we soon, what that mar- 

 velous vivifying influence is which sets this self -built cellular 

 mechanism at work, and keeps it going, as a rule, under favor- 

 able conditions until the shadows of threescore years and ten 

 begin to deepen about the worn machine. Nor has all our 

 gathered life lore led us far among the mysteries which cluster 

 about the vague region in which the spiritual and the material 

 meet and interfuse. But this we know, that all the things the 

 body does, from its high borderland achievements in thought and 

 memory down through the homely processes of nutrition and re- 

 pair, are accomplished by these small life units in accordance 

 with physical laws as definite and unvarying as are those which 

 we trace in plant and earth and star. 



Under a variety of adverse conditions the human body can 

 still hold its own and secure for a time a certain degree of health, 

 thanks to the adaptability to circumstances of its component 

 cells. Thus, by the nice control of its ceaseless chemical pro- 

 cesses, the body can maintain a nearly uniform degree of heat, no 

 matter what the latitude or season. Starve the body, and its cells 

 can feed for a while upon the stores which they have in times of 

 plenty laid aside. They struggle long and faithfully against the 

 manifold excesses which may be forced upon them. They fight 

 with fashion, in one sex at least, for space within this none too 

 roomy tabernacle, with business and with pleasure for a time to 

 rest, with drugs and blighting drinks and unwholesome foods for 

 release from poisons which it is not usually thought criminal to 

 administer to one's self. They work as best they can without the 

 wholesome air so frequently denied them. They resist with what 

 force they can muster inherited weaknesses or taints. 



