DIFFICULTIES 



animals. Many mice carry in their nose latent viruses which, 

 when any material is inoculated into the lungs through the nose, 

 are carried into the lungs where they multiply. If the lungs 

 from these mice are used to inoculate other mice in the same 

 way, pneumonia is sometimes set up and, as a result, it might 

 be wrongly concluded that a virus had been isolated from the 

 original material. Also in attempting to isolate a virus by 

 inoculating material on to the skin of experimental animals, it 

 is possible to set up a transmissible condition which originated 

 from the environment and not from the original inoculum. 



Early investigations on distemper of dogs incriminated as the 

 causal agent a certain bacterium isolated from cases of the 

 disease because on inoculation it set up a disease resembling 

 distemper. When later a virus was shown to be the true cause 

 of the distemper, it became apparent that the early investigators 

 had been misled either because they had isolated a pathogenic 

 secondary invader or because they had not taken sufficiently rigid 

 measures to quarantine their experimental dogs. 



When the investigator has done his best to detect any errors 

 in his work, a service that colleagues are usually glad to assist 

 with is criticism. He is a bold man who submits his paper for 

 pubUcation without it having first been put under the microscope 

 of friendly criticism by colleagues. 



SUMMARY 



The mental resistance to new ideas is partly due to the fact 

 that they have to displace established ideas. New facts are not 

 usually accepted unless they can be correlated with the existing 

 body of knowledge; it is often not sufficient that they can be 

 demonstrated on independent evidence. Therefore premature 

 discoveries are usually neglected and lost. An unreasoning, 

 instinctive mental resistance to novelty is the real basis of excessive 

 scepticism and conservatism. 



Persecution of great discoverers was due partly to mental 

 resistance to new ideas and partly to the disturbance caused to 

 entrenched authoritv and vested interests, intellectual and 

 material. Sometimes lack of diplomacy on the part of the 

 discoverer has aggravated matters. Opposition must have killed 



"9 



