WHAT IS PHYSICAL LIFE 



his patient from the inrush of unicellular 

 invaders, and the great triumphs of mod- 

 ern antiseptic surgery are due to the prac- 

 tical application of the great principle 

 that multicellular must be guarded at 

 every point from unicellular life. In 

 medicine the same principles are equally 

 important, because if any part of the pro- 

 tecting envelope is damaged by inflamma- 

 tion or injury, straightway an entrance for 

 the deadly old enemies is established. 



But a second and important line of de- 

 fence is found in the inherent power of 

 the healthy bodily cells to resist the in- 

 vaders. This is well illustrated by an 

 experiment in which after minute injuries 

 have been inflicted by long, fine, but steril- 

 ized needles in the liver, spleen, kidneys, 

 and limbs of rabbits, and then a virulent 

 culture of pus-forming bacteria is injected 

 into a vein of the rabbit's ear; these bac- 

 teria then circulate with the blood over the 

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