136 BIOLOGICAL ASPECTS OF HUMAN PROBLEMS 



carried on with its individual rhythm. There is 

 some resemblance between such a field and a room 

 containing a number of different machines operating 

 each with its own rhythm. Each of the machines 

 can be accelerated or retarded in rhythm, but such 

 change in rhythm causes no change in the quality 

 of the function the clocks, for example, develop no 

 new function in consequence of ticking more rapidly 

 or more slowly than they should. It is difficult to 

 believe, at first sight, that deranged cells develop no 

 new products or powers, but this seems to be the 

 case. Whether a cell is deranged by errors inherent 

 in organization, by the action of bacterial poisons 

 from without, or from the action of drugs, the effect 

 is the same in type. There is retardation or accelera- 

 tion of function, but probably no new development 

 of function. When we find in the blood or urine 

 substances that seem wholly strange and abnormal, 

 we are disposed to regard them as something quite 

 novel. When we look more deeply into the physio- 

 logical processes, we see in every case that these 

 pathological substances have their origin in accelera- 

 tions or retardations of normal function. One ex- 

 ample must suffice. The urine of diabetic persons 

 may contain a considerable amount of an abnormal 

 constituent known to chemists as a variety of 

 oxybutyric acid. In health no trace of this acid is 

 detectable in the urine. Whence does it come in 

 disease? For a long time it was impossible to 

 correlate this unfamiliar substance with any physio- 



