THE ART OF SCIENTIFIC INVESTIGATION 



because their independent minds rebelled against developing the 

 habit of accepting authority instead of seeking evidence. 



The views expressed in the preceding paragraph on the possible 

 harmful effect of learning languages are by no means widely 

 accepted. However, there is another consideration to be taken 

 into account when deciding whether or not to study a language, 

 or for that matter any other subject. It is that time and effort 

 spent in studying subjects not of great value are lost from the 

 study of some other subject, for the active-minded scientist is 

 constantly faced with what might be called the problem of com- 

 peting interests : he rarely has enough time to do all that he 

 would like to and should do, and so he has to decide what he 

 can afford to neglect. Bacon aptly said that we must determine 

 the relative value of knowledges. Cajal decries the popular idea 

 that all knowledge is useful; on the contrary, he says, learning 

 unrewarding subjects occupies valuable time if not actual space 

 in the mind.^^° However, I do not wish to imply that subjects 

 should be judged on a purely utilitarian basis. It is regrettable 

 that we scientists can find so little time for general Hterature. 



If the student cannot attend a course in biometrics, he can 

 study one of the more easily understood books or articles on 

 the subject. The most suitable that have come to my notice 

 are those of G. W. Snedecor,*'^ which deals with the applica- 

 tion of statistics to animal and plant experimentation, and 

 A. Bradford HilV^ which deals mainly with statistics in human 

 medicine. Topley and Wilson's text-book of bacteriology con- 

 tains a good chapter on the application of biometrics to bacteri- 

 ology.^^ Professor R. A. Fisher's two books are classical works, 

 but some people find them too difficult for a beginning.^ ^' ^° 

 It is not necessary for the biologist to become an expert at 

 biometrics if he has no liking for the subject, but he ought 

 to know enough about it to avoid either undue neglect or 

 undue respect for it and to know when he should consult a 

 biometrician. 



Another matter to which the young scientist might well give 

 attention is the technique and art of writing scientific papers. 

 The general standard of English in scientific papers is not high 

 and few of us are above criticism in this matter. The criticism 

 is not so much against the inelegance of the English as lack of 



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