PREPARATION FOR THE STUDY OF BIOCHEMISTRY 25 



pies of physical chemistry and there can be ho doubt whatever that the 

 future and most momentous developments of the subject are destined 

 to involve physical chemistry more and more extensively. The essen- 

 tial principles are neither numerous nor abstruse, good elementary 

 text-books of the subject abound and the student is earnestly recom- 

 mended, if he has not previously received training in this subject, to 

 acquire for himself a suitable handbook of physical chemistry, 1 and to 

 consult it frequently in the course of his studies in biochemistry. 



The intelligent employment of the elementary principles of physical 

 chemistry implies a nodding acquaintance with the so-called "higher 

 mathematics," but far more than for the mere understanding of 

 physical chemistry, mathematics is an essential instrument in the 

 handling of quantitative measurements of any kind whatsoever. 

 Every branch of science is, in its youth, qualitative, and in its maturity 

 quantitative. Even taxonomy has been converted by the discoveries of 

 Mendel into a quantitative study involving in some instances very 

 complex mathematical operations. Biochemistry is at the present 

 juncture passing through a species of adolescence and emerging by very 

 rapid stages from the qualitative into the quantitative stage of develop- 

 ment. The student who would prepare himself for the future, there- 

 fore, would do well to acquire such rudiments of mathematical skill 

 as may be necessary for the elucidation of principles which . he will 

 unquestionably be called upon to comprehend. Mathematics is in 

 reality a symbolic language which expresses in brief terms a series of 

 interrelated facts and considerations which would otherwise be too 

 intolerably complex to retain simultaneously in the mind. By acquir- 

 ing mathematical facility, therefore, the student is not augmenting 

 the complexity of his task, but simplifying it. 



The applications of physical chemistry to biological problems 

 necessitate of course an elementary knowledge of the differential 

 calculus and the simplest methods of integration. 2 All of the work 

 upon ferments and digestion in its quantitative and most important 

 aspects now demands the employment of the calculus. As an example 

 of the wider and at first sight unexpected applications of this mathe- 

 matical technique the reader is referred to the important work of Barcroft, 3 

 which has marked an epoch in our understanding of the respiratory 

 functions of the blood and which could never have yielded one tithe 

 of the information obtained without the employment of the methods of 

 the differential and integral calculus. 



A moderate familiarity with the elementary principles involved in 

 the solution of differential equations would also upon occasion be found 



1 For example, E. W. Washburn: An Introduction to the Principles of Physical 

 Chemistry, New York, 1915. A. Findlay: Practical Physical Chemistry, London, 1914. 



2 The student may consult J. Edwards: Differential Calculus for Beginners and 

 Integral Calculus for Beginners, while for the methods of applying the calculus to the 

 solution of scientific problems the student would do well to read Perry's Calculus for 

 Engineers, London, 1897. 



3 The Respiratory Function of the Blood, Cambridge, 1914. 



