324 



REPORT OF THE COMMISSIONER OF AGRICULTURE. 



cylinder, tapered at the ends, in which a fire is built, and this heated 

 furnace, being drawn along the furrow, destroys the worms. Previous 

 to this invention it was customary to strew dry staw along the furrow 

 and set fire to it, but this was often attended with danger. This heated 

 iron boat can be used without danger, and at the same time it serves to 

 keep the inside of the furrow in a smooth and firm condition. 



Fiff. 2. 



The potato-plant has for many years been exposed to the depreda- 

 tions of an insect commonly known as the potato-fly, {Cantharis vittata,) 

 now generally known under the name of Lytta vittata. Various modes of 

 treatment have been adopted for its extermination. Latterly a new 

 enemy has appeared, known as the Colorado beetle, {Boryphora decemli- 

 neata,) which is more destructive than the former. 



The unusual ravages of these, especially the latter, have awakened a 

 spirit of inquiry as to an appropriate remedy, and a number of valuable 

 inventions have resulted from such investigation. Among these, we find 

 one for sifting Paris green (arsenite of copper) upon the growing plants, a 

 view of which is shown in figure 3. But it has been seriously questioned 



whether the use of a deadly poison 

 upon food-producing plants is a jus- 

 tifiable proceeding. Is it not pos- 

 sible that the pores of plants thus 

 treated will absorb some of the poi- 

 sonous elements, thus rendering the 

 product unfit for the human stom- 

 ach ? It is, on the one hand, claimed 

 that in those sections of the country 

 Fig. 3. where Paris -green has been used 



no evil has resulted from its use. On the other hand, some well- 

 informed physicians claim that gastric diseases are more prevalent 

 where it is Ireely used than in adjoining sections where it is not used. 

 It is undoubtedly true that destruction by mechanical means is a safer 

 method. 



Among the mechanical devices there are two that seem to be quite 

 feasible. The one shown in figure 4 may be described as follows : The 



rear end of the machine is mounted upon 

 two wheels. A trough, Avith a runner- 

 like bow, containing some adhesive mat- 

 ter, is suspended upon each side of the 

 row. A vibrating arm or beam, carry- 

 ing whisps or brushes, is adjustably sus- 

 pended from the frame, and as the ma- 

 chine is pushed along astride the row of 

 plants tht insects are shaken into the 

 troughs, from which they arc unable to 

 escape. 



Another machine, constructed upon 

 the same general principle, instead of 



Fig. 4. 



having a trough, with adhesive matter, to entrap the insects, is pro- 



