74 Stevens— Science of Plant Pathology. [June 



waits upon chemistry; plant pathology upon plant physiol- 

 ogy, and chemistry in return receives valuable contribution 

 from both. Mathematics, physics and geology all contribute 

 to the general upbuilding. The sciences, though becoming 

 more divergent instead of becoming more independent, are 

 yearly becoming more dependent, each using the discoveries 

 of the others to gain new foothold or new tools in the search 

 for truth. Often it is the frontier territory lying between 

 two sciences which, belonging distinctively to neither, is 

 least worked, and therefore presents most promising territory 

 for conquest. Such is the history of the comparatively new 

 sciences of physical chemistry, physiological chemistry and 

 biometrics. 



Nor does the field belong exclusively to either the devotee 

 of pure science, so-called, or of applied science. The study 

 of problems seemingly most remote from any practical ends 

 has often proved fundamental in the upbuilding of vast indus- 

 trial growth. Bacteriology was born of crystallography. 

 The father of galvanic electricity was derided as the frog's 

 dancing master. Nor does the avowed object in view give a 

 sure key to the ultimate outcome. Alchemy, though never 

 attaining the end sought, hastened immeasurably the era of 

 industrial chemistry. Nor may it be said that applied science 

 is inferior, for without the application the fundamental prin- 

 ciples are of no avail in the promotion of the welfare of man. 



Intensive laboratory study with no object other than the 

 increase of knowledge of molecular construction has led to 

 the commercial production of many important compounds. 

 The present oat smut treatment by formalin owes its prac- 

 ticability equally to pure science in the chemical study that 

 rendered the production of formalin practicable at moderate 

 cost, and to pure science of the botanist who from mere 

 interest in fungous growth discovered the nature of para- 

 sitism, and to the practical scientist who applied the know- 

 ledge of the chemist and the botanist to the solution of a 



