24 PRINCIPLES OF BIOCHEMISTRY 



of thought lies in the fact that the otherwise circular speculations of 

 humanity, ever returning unprofitably to the point from which they 

 started, have had a thrust communicated to them which has deflected 

 them into a perpetually widening spiral, reaching further and ever 

 further into the infinite, promising knowledge commensurate only with 

 the immensity of the universe, and power to which no man dare set a 

 limit. 



If, then, our present conceptions in biochemistry are subject to rapid 

 and comprehensive modification this affords no legitimate basis for 

 scientific cynicism or indiscriminate scepticism. On the contrary it is 

 a hopeful augury, testifying to the youth of the subject and the vast 

 development that lies before it. No subject, indeed, promises more 

 immediate developments of stupendous significance to man. The 

 control of life itself, no less, is the alluring aim and destiny of the 

 medical and biological sciences and the basis of every step in the 

 acquirement of this control must inevitably be founded on a knowledge 

 of the chemical processes which underlie and constitute life. We may 

 be well content, with such a prospect before us, to resign absolute 

 certainty to the political doctrinaire. For ourselves, dwelling amid 

 uncertainties and hazards, advancing like bold navigators in uncharted 

 seas, we will turn our faces toward the new and wider horizons which 

 always lie before us. We will regard a hypothesis as an instrument of 

 research, like a balance, a burette, or better still a compass; a guide 

 and a stimulus to investigations, but a mere approximation to the truth 

 which we trust will gradually approach closer and yet closer to verity 

 as our knowledge grows in extent and proliferates in detail. 



THE PREPARATION REQUIRED FOR THE STUDY OF 

 BIOCHEMISTRY. 



No amount of courage and enthusiasm, however, will suffice to alto- 

 gether compensate for lack of preliminary training and acquired skill 

 in those branches of science upon which biochemistry is founded and 

 from which it originates. Biochemistry is in the first place and most 

 essentially an outgrowth from organic chemistry and an acquaintance 

 with the general principles of that science and the simpler laboratory 

 procedures most frequently employed in it, is as essential to the 

 understanding of biochemistry as a vocabulary of French words is to 

 the understanding of Moliere in the original. In this work I will 

 suppose the reader to be acquainted with organic structural formulas 

 and the general principles according to which they are- inferred from the 

 behavior of the substances to which they are applied. 1 



The modern developments of biochemistry and particularly those 

 which aim at the interpretation of the processes underlying the per- 

 formance of function, involve the application of the elementary princi- 



1 The reader whose previous training in this subject has been dencient may consult 

 E. V. McCollum, Organic Chemistry for Students of Medicine, New York, 1916. 



