BIOLOGY AND CHEMISTRY 



synthesis from their very elements. Even protein 

 matter seems to have lost its mysteries since we 

 learned from Emil Fischer's work that amino- 

 acids can be combined in the same way as they 

 occur in protein. Compounds of amino-acids 

 can be obtained which show all the main reactions 

 of protein substances. Emil Fischer, of Berlin, 

 was the same chemist who in 1886 discovered how 

 to prepare grape sugar from glycerin. A con- 

 siderable number of plant alkaloids have been also 

 artificially prepared in the course of the last five 

 decades. The most important colouring matters of 

 plants, for instance, alizarin and indigotin, are no 

 longer extracted from plants for technical pur- 

 poses, but are accessible from the products of coal- 

 tar. We see, then, that animal and plant sub- 

 stances are by no means peculiar to the realm of 

 organic nature. They are compounded within the 

 living cell and without it by the same chemical 

 laws. Our task in experimental Biology can only 

 be this, to explore the material in the living cell 

 which carries out the chemical changes in sub- 

 stances, and to control the reactions which take 

 place in Life. 



The following chapters try to show what success 

 has been attained in the endeavours of Science 

 in the bordering territories of Chemistry and 

 Biology. 



