The Microscope. 101 



p. Colorless; pedicle 5 to 6 times as long as the minute (trhm in.) 

 body V. mieroscojnca, From. 



p. Colorless; pedicle enclosing numerous green corpuscles. 



V. appuncta, From. 



p. Green, homogeneous ; pedicle 8 to 10 times as long as the body. 

 V. smaragdina, Stokes. 



r. Bead-like cuticular elevations solid V. monilata, Tatem. 



r. Bead like cuticular elevations nucleated. V. Loekwoodii, Stoke3. 



THE MICROSPECTROSCOPE. 



BY PROF. A. Y. MOORE. 



THE Microspectroscope, as used in the form of a spectroscopic 

 eye-piece, is one of the most convenient ways of examining 

 the light transmitted by various objects, both solid and liquid, 

 and of determining the position of the dark bands produced in 

 the continuous spectrum by the absorbtion of certain colors of 

 which light is composed. 



The principle of the spectroscope is comparatively simple. 

 A beam of light is admitted through a very narrow slit, after 

 which it passes through a prism of flint glass as is shown in Fig. 1 . 



By the unequal refrangibility of the various colors which 

 compose white light, this narrow beam of light is spread out 

 into a band of colors, the length of which will depend upon the 

 dispersive power of the glass of which the prism is made, and 

 the distance of the screen upon which the band is received ; 

 while the width is simply dependant upon the length of the slit. 

 The order of the colors, starting with the least refrangible end, 

 is dark red, red, orange, yellow, green, blue, and violet. 



It will be seen from Fig. 1 that the beam of light (which is 

 represented by the dotted lines) is refracted as well as dispersed. 

 This is a great inconvenience when this form of prism is used 



