EUCALYPTUS TREES. 139 



just as it discloses even the sources of many of the 

 most terrific and ravaging diseases of which the 

 human frame is the victim. The microscope, that 

 marvelous tool for discovery, has become, also, the 

 guardian of many an industry. The processes of 

 morbid growth, or the development and diffusion of 

 the minute organism, between which descriptive bota- 

 ny knows how to discriminate, are thus traced out as 

 the subtle and insidious causes which at times involve 

 losses that count by hundreds of thousands in a single 

 year, even in our yet small communities. But while 

 the microscope discloses the form and development 

 of the various minute organisms which cause, through 

 the countless numbers of individuals,' at times the 

 temporary ruin of many branches of rural industry, it 

 leaves us not helpless in our insight how to vanquish 

 the invaders. In correctly estimating the limits of 

 the specific forms, calling forth or concomitant with 

 some of the saddest human maladies, phytography 

 shares in the noble aim of alleviating human suffer- 

 ings, or restoring health and prolonging vital exist- 

 ence. 



But it comes most prominently within the scope of 

 this Industrial Museum to delineate for the agricul- 

 tural and forest section, in explanatory plates, the 

 morbid processes under which crops and timber may 

 succumb, and an industry be paralyzed or a country 

 be verily brought to famine ; it devolves on us, also, 

 simultaneously to explain the effect of remedial agents, 

 such as sound reasoning from inductive science sug- 

 gests or confirms. To array samples of all field 

 products which our genial clime allows us to raise 

 is doubtless the object of an instructive institution, 



