NECESSITY OF FREEDOM FROM ANXIETY. 273 



poses, giving scientific evidence in courts of law, deliver- 

 ing popular scientific lectures, writing scientific books, 

 &c., are not usually the most fruitful discoverers. 



It has been suggested that, by employing a sufficient 

 number of assistants to make the experiments, an experi- 

 enced investigator might make a much greater number 

 of discoveries, but this is hardly correct ; the limit to the 

 advantage of employing unskilled assistants is soon at- 

 tained, because in most researches each experiment re- 

 quires to be skilfully watched and its results carefully 

 studied, and the latter especially occupies much time, and 

 can only be effectually done by the investigator himself. 

 Moreover, it is not so much the number of experiments, 

 as the accuracy with which they are performed, the acute- 

 ness with which they are observed, and the intensity with 

 which the results are studied, which yield truth. Skilful 

 watching of an experiment often suggests its true explana- 

 tions, or detects a new truth which an ordinary assistant 

 would overlook. A multitude of experiments also, unskilfully 

 performed, are worse than useless, because they confuse 

 and mislead. It is chiefly in cases where a long series of 

 experiments or observations of a routine kind have to be 

 made, that an ordinary assistant can be of much service. 



If assistants possessing scientific genius are employed, 

 then the discoveries they make are largely due to that 

 genius, and the credit of these discoveries may be partly 

 claimed by them; and this circumstance has, in many 

 cases, given rise to unpleasant disputes as to whom the 

 honour of a discovery should be given to. For the purpose 

 of rearing investigators, the employment of skilled assist- 

 ants is good. Bergmann adopted that plan ; he contrived 

 experiments, and his pupils executed them ; he educated 

 several chemists, one of whom was Scheele ; and Bergmann 



