88 SUMMARY OF CURRENT RESEARCHES RELATING TO 



objects need different treatment. When mounting the deposit obtained 

 from a water, or the washed residue from Demerara sugar, a conical 

 settling-glass is provided, aud when all suspended matters have settled, 

 as much as possible of the supernatant fluid is decanted off until only a 

 drop or two remains. The drop that is left, containing the residue of 

 suspended matter, is poured over the bead of glycerin-jelly already 

 solidified on a slide. By now placing this slide overnight in a level 

 position in a desiccator, the water will be found next day to have become 

 absorbed, leaving the sediment in position on the surface of the jelly. If 

 now gently warmed and a cover-glass adjusted, any fine residue of 

 suspended matter from water can be more successfully retained and fixed 

 by such means than the usual methods of treatment allow. 



(6) Miscellaneous. 



Crystallization of Coumarin.* — At the November Meeting, 1913, 

 Gr. H. Beaumont exhibited slides illustrating the crystallization of 

 Coumarin (from Tonkin Bean). These slides were prepared by fusion. 

 When cooled at the ordinary temperature, Coumarin crystallizes in a 

 translucent grey- white mass, and shows little or no colour when viewed 

 by polarized light. When allowed to cool more slowly it sometimes 

 exhibits characteristic fan-like crystallization which is weakly doubly 

 refracting. When crystallized under pressure it becomes highly doubly 

 refracting, and exhibits the fine colour effects which were shown in the 

 exhibits. 



