3 o SCIENCE 



quantity. To what extent is the presence of 

 impurity detrimental, what are the impurities 

 which must be removed, what are the steps 

 required to do this on the requisite scale, to 

 what extent do the difficulties involved in this 

 render the whole method commercially im- 

 possible by adding seriously to the cost? Is 

 there any difference between the material 

 made in quantity and that produced by the 

 laboratory furnace, where rapid cooling or 

 heating may be readily employed, although 

 impossible in the full scale work, and so on? 

 For the industrial research laboratory the 

 plant, etc., must be so planned that it is 

 possible to carry out the necessary operations 

 on a scale comparable with that required in 

 works, and, moreover, the man who carries 

 through the investigation must be not only 

 acquainted with the latest scientific advances 

 in his subject, but must know what is possible 



