APPARA TVS FOR SCIENTIFIC DEMONSTRA TION 1 57 



Two detached lanterns have some obvious advantages, 

 where detached or side experiments are of frequent occurrence. 

 But in perhaps the majority of cases the demonstrator, equally 

 with the exhibitor, may find it most advantageous to employ 

 a bi-unial or even tri-unial arrangement, modified, however, 



_A Microscopic Bi.unial 



according to his special purposes. This is especially the plan 

 where the lime-light is the radiant employed. The simplest 

 case is perhaps that of a medical school, which may desire to 

 supplement the demonstrations of such a lantern microscope 

 as is described in the following chapter, by photo-micrographs 



