APPENDIX. 



SELECTIONS. 



On Smut in Wheat. 



The opinion advanced by Mr. Somerville and others ^ 

 of the animalcular nature of the disease called smut in 

 wheat, is supported by Robert Harrup in Nicholson's 

 Philosophical Journal, Vol. 13, p. 113. "The black 

 dust, he remarks, consists of globules, which are hea- 

 vier than water, with which they readily mix, but soon 

 subside, suffering no change by being kept in that fluid. 

 In the beginning of September, I infused some of the 

 pow^der in water in a watch-glass. A few hours after, 

 I discovered by the microscope, in a drop of the fluid, 

 a few animalcuise. Upon examination, next day, every 

 drop of the liquor contained innumerable animalculas, 

 generally very minute, but some a size larger. After 

 standing exposed some days, the water evaporated, and 

 an hour or two after the addition of fresh water, every 

 part swarmed with animalculae, moving nimbly in all 



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