^°57.J TJie Microscope. 275 



to be cross, and sting badly, but in a pleasant clear atmosphere there 

 is no danger. Some use screens of various kinds in hiving or work- 

 ing with bees, and it is well to have a bee dress in readiness to meet 

 certain circumstances, such as just named ; but ordinarily one will 

 not use it when accustomed to bee management. 



"We shall next discuss the economy of bee-keeping in this country, 

 also of feeding bees, Patent hives, etc. ; our views of the bee 

 moth how to prevent their ravages, etc. We shall be able to show 

 many interesting phenomena, in the Apiary connected with the 

 Agronomic department of our College. 



THE MICROSCOPE. 



("see engraving.) 



From being a mere toy, the compound microscope has risen to the 

 front rank amongi nstruments used by the Naturalist, in his investiga- 

 tions. It is indeed impossible to pursue scienti fie studies, to even a 

 moderate extent, without its aid. Only a few years since, thesimple 

 microscope was much more reliable than the compound for any care- 

 ful, accurate investigation. In the latter instrument, an enlarged 

 image of the object is first formed, and then this image is magnified 

 by a simple microscope, and it is evident that if we are to have dis- 

 tinct vision, the image must be formed with the utmost exactitude. 

 Ordinary lenses have two serious defects which prevent them from 

 forming such an image. One of these defects, is, that the outer por- 

 tions refract the rays more than the central portions, and thus pre- 

 vent their meeting in the same point ; the other defect, is, that light, 

 when refracted, is always split into seven colors, each of which 

 travels its own road, and thus, again, their meeting in the same 

 point is prevented ; and unless all the rays falling on a lens from 

 any one part of an object are accurately refracted to the same 

 mathematical point, the image it forms will be distorted and imper- 

 fect. The errors described above can nearly all be corrected by mak- 

 ing lenses, of two kinds of glass, crown and flint, which differ iu 

 their dispersive power, as it is termed. Each good object glass must 



