364 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



pulleys w under which pass the limbs of the cord-loop. The ocular 

 part of the Microscope-tube is mounted on a strong metal base-plate 

 which, by means of a dovetailed groove, rests on a cast-iron bar sup- 

 ported by the upright beams m of the projection chamber. At the 

 left-hand end of this bar is a hinge (not visible in figure) so that the 

 bar and instrument can be raised, and by means of the hook n kept 

 in an oblique position if projection apparatus of another kind should 

 be required. At the right-hand end a strong spring o suffices to keep 

 the bar in its place. The lantern is one of Newton's " patent electric 

 lantern Microscope and micropolariscopes." 



(4) Photomicrography. 



Study of Growing Crystals by Instantaneous Photomicro- 

 graphy.* — Messrs. Eichards and Archibald in their experiments used 



Fig. 80. 



Bausch and Lomb's ordinary pbotomicrographic apparatus with a 

 vertical camera. Between the Microscope F (fig. 80) and the camera 

 in a suitable light-tight box B, was placed a revolving shutter, which 



• Amer. Chem. Journ., xxvi. (1901) pp. 61-74 (16 figs, and pis.). 



