2 I'KKSJDKNT S ADDRESS. 



selection of the town of Port Elizabeth as the meeting-place for 

 1912 seemed to indicate that my address should be connected 

 with the economical side of science, particularly in reference to 

 the application of biological principles to the branch in which T 

 have been engaged — I might call it " Theory and Practice " in 

 the investigation of Stock diseases of South Africa. Port 

 Elizabeth is renowned for its best Agricultural Shows ; for many 

 years past it has held the record, and the people of this town 

 mean to keep up their reputation in the future; it is also famous 

 for its ostrich-feather market, and it commands the greatest wool 

 exporting trade of South Africa. These facts are the connecting 

 links with the practical science of Agriculture. But Port Eliza- 

 beth also maintains a Museum practically unsupported by State 

 assistance ; for its upkeep it relies principally on the resources of 

 this town, a fact which shows that the inhabitants of this town 

 take also an interest in pure science. 



Generally speaking, the South African is decidedly of a 

 practical disposition, and the utility of any investigation is the 

 first thing with which he is concerned. This can be well under- 

 stood by those who come in close contact with the population, 

 and who realise all the difficulties which an inhabitant of this 

 sub-continent has to face in his struggle for existence. 



Whilst I readily admit that in our investigations the 

 economical side should always be considered first of all, yet, if 

 we really want to ensure steady progress, we must not let the 

 utilitarian point overshadow other considerations. When we 

 begin a scientific investigation we never know where it will finally 

 lead to. What appears to one man as useless will be turned to 

 good account by another. Some people have no use for pure 

 sciences, whilst to others it represents the whole object of their 

 lives. Science is a result of advanced civilisation, and, in my 

 opinion, it must be employed to serve mankind both for his 

 intellectual and economical development. In South Africa the 

 people who apply science to everyday requirements are called 

 experts. T believe T am correct in saying that the expression 

 was imported from America. One frequently hears the objec- 

 tion that their conclusions and recommendations are too 

 theoretical, and as such are useless for the purpose of the 

 practice, but this view can only be the result of a misunder- 

 standing. When investigations have been made, and when n 

 number of facts have been recorded, then they require to be 

 interpreted, and to do this they are explained by connecting 

 them with already established principles. For this purpose 

 theories are necessary ; they are the rays of light in the chaos of 

 observations which at first sight frequently seem totally contra- 

 dictory. There is hardly any theory which has not done some- 

 thing towards clearing up the obscurity of the problem, and J 

 will show that in the investigation of diseases there are theories 

 based on well-established points and formed by comparisons 

 with other conditions which are capable of explaining observa- 



