VI PREFACE 



When, as sometimes occurs, the biologist is called in 

 to deal with the biological sides of the problem, his 

 success is frequently limited to pointing out errors in 

 the chemist's biological theories. The reason for this 

 limitation is the paucity of information on the biological 

 side. Whereas biology is probably more complicated 

 than chemistry, vastly more man-hours have been de- 

 voted to chemical research than to biological research. 

 When this situation is remedied, it will be possible for 

 the biological side of drug development to proceed in a 

 rational manner. This will eliminate the hit or miss tech- 

 nique, which is now the main basis of the search for new 

 drugs. For chemists this will mean much diminution of 

 effort — probably 90% or more of the time used for syn- 

 thesis of useless compounds can be eliminated. And for 

 biologists there will be a corresponding diminution in 

 the time spent in testing inactive compounds. 



Consequently my hope is that these lectures will play 

 some little part in directing attention to the biological 

 aspects of drug action, and in showing that studies in 

 the biological field are practicable. 



I am deeply indebted to Prof. A. Haddow for advice 

 and for reading the galley proofs. 



J.F.Danielli 



