BIOLOGICAL PHILOSOPHY 399 



THE LIVING MACHINE * 

 R : T . YOUNG 



Is there one law for the living and another for the dead, or is the universe 

 a unit in its workings and all matter governed by universal law? The former 

 is the contention of the "vitalist," the latter of the "mechanist." What is 

 life? Is it some inscrutable process, controlled by a "vital principle" operat- 

 ing outside the realm of physics and of chemistry? Or is it merely a special 

 expression of the forces which control inorganic matter. Our only answer 

 to these questions is that we do not know. Neither the substance nor the 

 energy of life has ever been analyzed, and the only way in which we can 

 identify life is by its manifestations. What are these manifestations, and 

 what light if any do they throw upon the ultimate nature of life itself? 



Firstly, what is the stuff of which living things are made? An analysis 

 of living substances or protoplasm is exceedingly difficult if not impossible. 

 In order to analyze it, it must be killed, and the readiness with which the 

 protoplasm breaks down into innumerable simpler substances leads us to 

 suspect that after protoplasm is killed it is protoplasm no longer, so that 

 we are analyzing not protoplasm at all, but something else. Our analyses 

 are sufficient to show us however that protoplasm contains the same ele- 

 ments of which inorganic matter is composed, united into a marvellously 

 complex whole. The manifold varieties of life which we know lead us to 

 believe in as great a variety of protoplasm which determines this variability 

 in living things. In spite of its variability however all protoplasm alike 

 contains protein consisting of carbon, hydrogen, nitrogen, oxvgen and 

 sulphur, without which it cannot exist. Protein however is found outside 

 of protoplasm in egg albumin for example and in the various albumins and 

 globulins of the blood. These substances while protoplasmic products are 

 not protoplasm itself; hence we see that in its composition (in some partic- 

 ulars at least) living matter does not differ fundamentally from non-living. 



One of the most characteristic features of hfe is its power of waste and 

 repair and growth. It is folly to attempt, as some have done, to compare 

 these processes in their entirety with any process in the non-living world. 

 There is nothing with which it can be compared. And yet if we analyze 

 them into their component processes, we find that they are composed of a 

 series of chemical and physical reactions, many of which at least can be 

 exactly reproduced in the laboratory. 



In the warm spring days when the remnants of last year's crop of po- 

 tatoes in the cellar start to sprout, and those which are served upon your 

 table have an unpleasant sweetish taste, you are the victim of a ferment (or 

 enzyme) known as diastase, of wide-spread if not universal distribution 



• From Biology in America by R. T. Young, copyright 1922 by Chapman and 

 Grimes, Boston. 



